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