Tennessee Onions Recipe – Easy Cheesy Baked Side Dish for Dinner

Introduction

The first time I pulled a pan of Tennessee onions out of the oven, my whole kitchen was filled with this unreal, savory aroma—like a cross between French onion soup and gooey cheese toast. I swear, it’s the kind of scent that makes neighbors peek over the fence and ask, “What’s cooking?” My love affair with this cheesy baked onion side dish started back when I was visiting Nashville. We stopped at a quirky little diner, and the server brought out a bubbling casserole that looked plain at first. But then I took a forkful—whoa! Tender, sweet onions blanketed in melted cheese, with a hint of butter and herbs. It was pure comfort food, southern style, and I was hooked.

I’ve made this Tennessee onions recipe more times than I can count, and honestly, it never disappoints. It’s the perfect side dish for busy weeknights, potlucks, or any dinner where you want the veggies to steal the show. You only need a handful of ingredients, and most of them are probably hanging out in your fridge right now. If you’re feeding picky eaters (or just trying to sneak in more veggies), this is one of those magic recipes that gets everyone excited about onions. And if you’re a fan of cheesy casseroles, you’re in for a treat.

What I love most? These Tennessee onions are so forgiving. I’ve tested different cheeses, swapped in gluten-free breadcrumbs, and even played around with the seasonings. No matter what, you end up with a side dish that’s golden, bubbling, and packed with flavor. So grab your onions—and let’s make a southern classic that’ll have everyone asking for seconds.

Why You’ll Love This Recipe

• Quick & Easy: You only need about 10 minutes of prep time—just slice, layer, and bake.
• Simple Ingredients: No fancy shopping trips required. If you’ve got onions, cheese, and a bit of butter, you’re halfway there.
• Perfect for Any Occasion: This Tennessee onions recipe is a hit at everything from backyard barbecues to cozy holiday dinners.
• Crowd-Pleaser: Honestly? People who say they don’t like onions somehow fall in love with this dish. Kids, adults, neighbors—everyone comes back for more.
• Unbelievably Delicious: The combo of sweet onions, savory cheese, and buttery herbs is just next-level comfort food. It’s the kind of dish you close your eyes and savor.

I’ve made a lot of cheesy casseroles, but Tennessee onions are unique. The secret is how the onions soften and sweeten as they bake, soaking up the flavors of the cheese and butter. I always blend a couple of different cheeses for the best texture—sharp cheddar for bite, mozzarella for stretch, and sometimes a sprinkle of parmesan for salty tang. If you want that classic southern flavor, don’t skip the dash of garlic powder and a sprinkle of fresh parsley.

This recipe stands out because it’s more than just cheesy onions—it’s a little bit nostalgic, a little bit clever, and totally customizable. It’s the side dish you whip up when you need something hearty and satisfying, but don’t want to fuss. I’ve served it at potlucks where it vanished in minutes, and even picky eaters asked for the recipe. You know, it’s one of those dishes that makes you feel like a kitchen rockstar. If you’re looking for a new favorite side, Tennessee onions are it!

Ingredients Needed

This Tennessee onions recipe is all about simple, wholesome ingredients coming together for big flavor. You probably have most of these in your kitchen already, and if not, there’s plenty of room to improvise.

• Yellow onions, 3-4 large (about 2 lbs / 900g), peeled and sliced into 1/2-inch rounds (sweet onions like Vidalia or Walla Walla work great too)
• Sharp cheddar cheese, 1 cup (about 115g), shredded (for bold flavor)
• Mozzarella cheese, 1 cup (about 115g), shredded (for gooey texture)
• Parmesan cheese, 1/2 cup (45g), grated (adds a salty kick)
• Unsalted butter, 6 tablespoons (85g), melted (for richness)
• Garlic powder, 1/2 teaspoon (for savory depth)
• Salt, 1/2 teaspoon (adjust to taste)
• Black pepper, 1/4 teaspoon (freshly cracked is best)
• Italian seasoning, 1 teaspoon (or dried thyme/oregano—whatever you have handy)
• Fresh parsley, 2 tablespoons, chopped (for garnish—optional, but recommended)
• Bread crumbs, 1/2 cup (50g), plain or panko (for topping, optional)

Ingredient Notes:

• If you’re out of mozzarella, swap in Monterey Jack or Colby. They melt beautifully.
• I love using sweet onions when they’re in season, but regular yellow onions work just fine. Don’t use red onions—they’re too strong for this dish.
• If you need a gluten-free option, just skip the breadcrumbs or use gluten-free panko. Easy.

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• Brand Tip: I always reach for Cabot cheddar or Tillamook if I can—they melt like a dream.
• If you want to make it dairy-free, sub in vegan cheese and plant-based butter. It’s not quite the same, but it still tastes pretty darn good.

These ingredients are all about building layers of flavor and texture. You get that sweet, caramelized onion base, creamy melted cheese, and a buttery finish. That’s southern comfort in a casserole dish!

Equipment Needed

You don’t need a fancy kitchen setup for this Tennessee onions recipe. It’s all about using what you have. Here’s what I always grab:

• 9×13-inch (23x33cm) baking dish: Glass or ceramic works best for even heat.
• Sharp chef’s knife: For slicing those onions into perfect rounds. A mandoline makes it even easier (just watch your fingers—I’ve learned the hard way).
• Cutting board: Wood or plastic, whichever you prefer. I go for the largest one to keep onion slices tidy.
• Mixing bowls: For tossing onions with seasonings and for mixing cheeses.
• Measuring cups and spoons: Accuracy helps, especially with the seasonings.
• Aluminum foil: For covering the dish during the first part of baking, so the onions steam and soften without burning.
• Oven mitts: Hot casserole, hot hands!
• Spatula or serving spoon: For scooping out those cheesy layers.

If you don’t have a 9×13 dish, a couple of smaller baking dishes work fine—just keep an eye on the bake time. I’ve used Pyrex, ceramic, and even metal pans. The only thing to watch out for is nonstick coatings (sometimes the cheese sticks more). For cleaning, a quick soak with hot water and a little baking soda makes cheesy pans easy to wash.

On a budget? Dollar store pans do the trick. I’ve made Tennessee onions at friend’s houses with whatever was handy, and it always turns out delicious.

Preparation Method

1. Preheat your oven: Set it to 375°F (190°C). While it heats, grab your baking dish and lightly grease it with butter or nonstick spray.
2. Prep the onions: Peel 3-4 large yellow onions. Slice into 1/2-inch rounds—don’t go thinner, or they’ll fall apart. If your eyes water, chill the onions beforehand or slice near an open window (my grandma’s trick!).
3. Layer the onions: Arrange the rounds in the baking dish in a single layer, slightly overlapping. I like to fill the dish edge to edge for an even bake.
4. Season: Sprinkle the garlic powder, salt, pepper, and Italian seasoning over the onions. Toss gently with your hands (or use tongs) to coat evenly. If you love a little extra kick, add a dash of cayenne.
5. Mix the cheese: In a bowl, combine shredded cheddar, mozzarella, and parmesan. Give it a quick toss to blend.
6. Top the onions: Sprinkle the cheese mixture evenly over the seasoned onions. Don’t pack it down—let it melt into the cracks and crevices.
7. Add butter: Drizzle the melted butter all over the cheese and onions. (Trust me, don’t skip this step. The butter helps everything brown and bubble.)
8. Add breadcrumbs (optional): Sprinkle 1/2 cup breadcrumbs over the top for a crunchy finish. If you’re gluten-free, skip this or use GF crumbs.
9. Cover and bake: Cover the dish loosely with foil and bake for 25 minutes. This lets the onions steam and soften without burning the cheese.
10. Uncover and bake: Remove the foil and continue baking for 15-20 minutes, until the cheese is golden and bubbling. The edges should be slightly caramelized, and the onions tender when pierced with a fork.
11. Garnish and serve: Sprinkle with fresh parsley right before serving. Let the dish sit for 5 minutes—it’ll firm up and be easier to scoop.

Troubleshooting Tips:

• If the cheese browns too quickly, tent with foil again for the last 10 minutes.
• If your onions are super strong, soak the slices in cold water for 10 minutes, then drain and pat dry before layering.
• For extra caramelized onions, bake uncovered for an additional 5 minutes at the end.

When you scoop into the casserole, the onions should be soft, sweet, and coated in gooey cheese. The smell alone will make everyone hungry!

Cooking Tips & Techniques

Here’s where the magic happens! Over the years, I’ve learned a few tricks to make sure your Tennessee onions turn out perfect every time:

• Choose the right onions: Sweet yellow onions work best. If you use regular yellow onions, let them soak in cold water for 10 minutes to mellow out the flavor.
• Slice evenly: Uniform thickness means the onions will cook at the same rate. If you end up with a few thinner slices (it happens), tuck them under thicker ones so they don’t burn.
• Cheese blend matters: Mixing cheddar and mozzarella gives you both flavor and stretch. If you use only cheddar, the dish is a little oilier but still delicious.
• Don’t skimp on butter: The melted butter is what gives the onions that roasted, rich flavor. I tried cutting back once—regretted it big time.
• Bake covered, then uncovered: The two-step baking method is key. Covered, the onions steam and soften. Uncovered, the cheese gets bubbly and golden.
• Watch the oven: If your casserole is browning too fast or unevenly, rotate the dish halfway through. Every oven has its quirks!
• Let it rest: As tempting as it is to dive right in, give the casserole 5-10 minutes to set after baking. It’ll be easier to serve (and you won’t burn your tongue—been there, done that).

One time, I forgot to cover the dish and ended up with onions that were a little too chewy. Lesson learned! If you want extra crispy breadcrumbs, broil for 1-2 minutes at the end, but watch closely—it goes from golden to burnt in a flash.

Timing is important. You can slice and season your onions while the oven preheats, mix your cheeses as you go, and have everything ready to bake in less than 15 minutes. It’s multitasking at its finest.

Variations & Adaptations

Tennessee onions are endlessly customizable. Here are a few of my favorite twists:

• Low-carb version: Skip the breadcrumbs or use crushed pork rinds for a keto-friendly topping. I’ve tried this—extra crunch, zero carbs!
• Spicy kick: Add a sprinkle of red pepper flakes or a dash of hot sauce to the cheese mix. Perfect for those who like a little heat.
• Dairy-free adaptation: Use vegan cheese shreds and plant-based butter. The texture isn’t quite as gooey, but the flavor is still really good.
• Seasonal swap: In the summer, mix in thinly sliced zucchini or bell peppers for color and extra flavor.
• Herb lovers: Swap Italian seasoning for fresh thyme and rosemary if you have it. It smells amazing and tastes even better!
• Classic casserole style: Add a layer of cooked rice or potatoes under the onions for a heartier dish—like a southern gratin.

For allergies, gluten-free breadcrumbs work great, and you can always swap out cheeses for what’s safe for your family. My personal favorite variation? I add a handful of crumbled bacon on top before baking. It’s not traditional, but wow, does it taste good!

Don’t be afraid to experiment. This Tennessee onions recipe is forgiving—a little more cheese, a pinch less butter, or a different herb, and it’s still delicious.

Serving & Storage Suggestions

Tennessee onions are best served hot and fresh from the oven, when the cheese is bubbling and the edges are golden. I like to scoop generous portions onto plates and sprinkle with fresh parsley—it looks pretty and adds a pop of flavor.

• Serving temperature: Hot is best, but room temp is surprisingly tasty, too.
• Presentation: Serve in the baking dish for a rustic look, or transfer to a pretty platter for holidays. The cheese and onions layer beautifully.
• Pairings: These onions go with grilled chicken, steak, or pork chops. I’ve even served them with burgers and BBQ ribs—seriously, they’re perfect with anything savory.
• Beverage suggestions: Try a cold iced tea or a crisp white wine to balance the rich, cheesy flavors.

For storage, cover leftovers tightly and refrigerate for up to 3 days. The flavors deepen overnight, so the next-day leftovers are almost better! To reheat, microwave covered portions for 1-2 minutes, or pop the whole dish in a 350°F (175°C) oven for 10-15 minutes until warmed through. If the cheese looks dry, sprinkle a little water or extra butter on top before reheating.

You can freeze Tennessee onions, but the texture of the onions and cheese may change a bit. If you do freeze, thaw overnight in the fridge and reheat in the oven for best results.

Nutritional Information & Benefits

This Tennessee onions recipe packs a surprising nutritional punch, thanks to its simple, wholesome ingredients. Here’s a rough estimate per serving (based on 8 servings):

• Calories: About 220
• Protein: 8g
• Fat: 15g
• Carbs: 14g

Onions are full of vitamin C, fiber, and antioxidants. They’re great for supporting immune health and digestion. The cheese delivers calcium and protein, making this side dish more filling. If you go easy on the butter and breadcrumbs, it’s relatively low-carb and gluten-free adaptable. Allergens? Watch out for dairy and gluten, but both are easy to swap with plant-based or GF alternatives.

From a wellness perspective, I love how this recipe makes onions the star. It’s hearty, satisfying, and a sneaky way to get more veggies into dinner—something I’m always aiming for in my own kitchen.

Conclusion

If you’re searching for a new side dish that’s simple to make but big on flavor, this Tennessee onions recipe is it. The combo of sweet baked onions and melting cheese is comfort food at its best (and, honestly, it’s so easy you’ll end up making it often). Whether you stick to the classic or try a twist, you can customize it for your family’s tastes, dietary needs, or whatever cheese you have in the fridge.

I love this recipe because it turns humble onions into something spectacular. Every time I serve it, folks ask for the recipe—and I always tell them, “It’s way easier than you’d think!” So go ahead, give these cheesy baked Tennessee onions a try. I’d love to hear how you make it your own, so drop a comment below or share your favorite variation. Happy cooking!

Your next dinner just got a whole lot tastier.

FAQs

Can I make Tennessee onions ahead of time?

Yes! Assemble the casserole up to a day in advance, cover, and refrigerate. Bake as directed when ready to serve. You may need to add a few extra minutes if baking straight from the fridge.

Do I have to use all three types of cheese?

Nope. You can use just cheddar, or any combo you like. Mozzarella adds stretch, and parmesan gives a salty kick, but the recipe is flexible.

How do I keep my onions from tasting too strong?

If your onions are extra pungent, soak the slices in cold water for 10 minutes before layering. This mellows out their flavor nicely.

Can I make Tennessee onions gluten-free?

Absolutely! Just skip the breadcrumbs or use gluten-free panko. The rest of the recipe is naturally gluten-free.

What’s the best way to reheat Tennessee onions?

Cover and microwave individual portions for 1-2 minutes, or reheat the whole dish in a 350°F (175°C) oven until hot and bubbly. Add a splash of water or butter if the cheese seems dry.

Tennessee Onions Recipe – Easy Cheesy Baked Side Dish for Dinner

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• Author: Lauren Diaz
• Total Time: 55 minutes
• Yield: 8 servings 1x

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Description

Tender, sweet onions are baked with a blend of melted cheeses, butter, and herbs for a comforting southern side dish. This easy casserole is perfect for weeknights, potlucks, or any dinner where you want veggies to steal the show.

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Ingredients

Scale 1x2x3x

• 3–4 large yellow onions (about 2 lbs), peeled and sliced into 1/2-inch rounds (sweet onions like Vidalia or Walla Walla work too)
• 1 cup sharp cheddar cheese, shredded
• 1 cup mozzarella cheese, shredded
• 1/2 cup parmesan cheese, grated
• 6 tablespoons unsalted butter, melted
• 1/2 teaspoon garlic powder
• 1/2 teaspoon salt (adjust to taste)
• 1/4 teaspoon black pepper
• 1 teaspoon Italian seasoning (or dried thyme/oregano)
• 2 tablespoons fresh parsley, chopped (for garnish, optional)
• 1/2 cup plain or panko bread crumbs (optional, for topping)

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Instructions

1. Preheat oven to 375°F (190°C). Lightly grease a 9×13-inch baking dish with butter or nonstick spray.
2. Peel and slice onions into 1/2-inch rounds.
3. Arrange onion rounds in the baking dish in a single, slightly overlapping layer.
4. Sprinkle garlic powder, salt, pepper, and Italian seasoning over onions. Toss gently to coat.
5. In a bowl, combine shredded cheddar, mozzarella, and parmesan cheeses.
6. Sprinkle cheese mixture evenly over the seasoned onions.
7. Drizzle melted butter over the cheese and onions.
8. Sprinkle bread crumbs over the top for a crunchy finish (optional).
9. Cover dish loosely with foil and bake for 25 minutes.
10. Remove foil and bake uncovered for 15-20 minutes, until cheese is golden and bubbling and onions are tender.
11. Sprinkle with fresh parsley before serving. Let sit for 5 minutes before scooping.

Notes

For gluten-free, skip breadcrumbs or use GF panko. Sweet onions are best, but yellow onions work. Soak onions in cold water for 10 minutes if they’re strong. Cheese blend is flexible—use what you have. Let casserole rest 5-10 minutes before serving for best texture. For extra crunch, broil for 1-2 minutes at the end. Leftovers keep well in the fridge for up to 3 days.

• Prep Time: 10 minutes
• Cook Time: 40-45 minutes
• Category: Side Dish
• Cuisine: Southern, American

Nutrition

• Serving Size: 1/8 of casserole
• Calories: 220
• Sugar: 6
• Sodium: 350
• Fat: 15
• Saturated Fat: 9
• Carbohydrates: 14
• Fiber: 2
• Protein: 8

Keywords: Tennessee onions, cheesy onions, baked onions, southern side dish, casserole, comfort food, easy recipe, potluck, gluten-free option