Cheesy Baked Sweet Onion Casserole Recipe
Tennessee Onions is a flavorful baked side dish featuring sweet onions layered with a blend of cheddar, Monterey Jack, and Parmesan cheeses, seasoned with garlic, thyme, and black pepper, then baked to a golden, bubbly perfection.
- Prep Time: 10 minutes
- Cook Time: 35 minutes
- Total Time: 45 minutes
- Yield: 6 servings
- Category: Side Dish
- Method: Baking
- Cuisine: American
Ingredients
Main Ingredients
- 3 large sweet onions (such as Vidalia), sliced into ½-inch rings
- 1 ½ cups shredded cheddar cheese
- 1 cup shredded Monterey Jack cheese
- ½ cup grated Parmesan cheese
- 4 tablespoons unsalted butter, melted
- 1 teaspoon garlic powder
- ½ teaspoon dried thyme
- ½ teaspoon salt
- ¼ teaspoon black pepper
Instructions
- Preheat the oven: Preheat your oven to 375°F (190°C) and lightly grease a 9x13-inch baking dish to prevent sticking and ensure even cooking.
- Prepare the onions: Arrange the sliced sweet onions in an even layer in the prepared baking dish, making sure to separate the rings for uniform cooking and cheese coverage.
- Add seasoning and butter: Drizzle the melted unsalted butter evenly over the onions. Then sprinkle garlic powder, dried thyme, salt, and black pepper on top to infuse the onions with flavor.
- Layer the cheeses: Evenly top the onions with the shredded cheddar, Monterey Jack, and grated Parmesan cheeses to create a rich and melty cheese crust.
- Bake covered: Cover the dish with aluminum foil and bake in the preheated oven for 25 minutes. This allows the onions to soften and the flavors to meld without the cheese overbrowning.
- Bake uncovered: Remove the foil and continue baking for another 10 minutes, or until the cheese is golden brown and bubbly, providing a delicious crispy cheese topping.
- Cool and serve: Let the dish cool slightly before serving to allow the cheese to set a bit. Serve warm as a tasty side dish to complement various mains.
Notes
- To prevent onions from becoming soggy, ensure rings are well separated before adding cheese.
- You may substitute sweet onions with yellow onions, but the flavor will be less sweet and more pungent.
- Use unsalted butter to control the overall saltiness; adjust salt according to taste.
- For a sharper cheese flavor, increase the amount of Parmesan cheese slightly.
- Covering the dish during the first bake helps onions become tender without burning cheese.
- Letting the dish cool before serving helps the cheese top to set nicely and makes serving easier.
