Onions are often considered a humble ingredient, but this Cheesy Tennessee Onion Casserole takes them to a whole new level. Sweet onions, combined with a trio of cheeses, create a rich, flavorful side dish that’s both comforting and indulgent. Whether you’re serving this casserole at a holiday gathering, a potluck, or a simple family dinner, it’s bound to be a hit with its savory layers and gooey, cheesy goodness.
Ingredients
- 3-4 sweet onions (approximately 700g), sliced into ¼ inch rounds
- 4 tablespoons butter (56g)
- 1 teaspoon salt (5g), or to taste
- 1 teaspoon garlic powder (2g)
- 1/2 teaspoon dried oregano (1g)
- 1 cup shredded Italian blend cheese (113g)
- 1 cup shredded cheddar cheese (113g)
- ½ cup shredded Parmesan cheese (56g)
Instructions
1. Prepare the Onions:
Start by preheating your oven to 375°F (190°C). Onions are the star of this dish, so it’s important to choose the right type. Sweet onions like Vidalia or Walla Walla are ideal because of their mild flavor and natural sweetness, which will balance the rich, cheesy layers. Peel the onions and slice them into ¼ inch rounds, aiming for uniform thickness so they cook evenly.
2. Sauté the Onions:
In a large skillet, melt 4 tablespoons of butter over medium heat. Butter not only adds flavor but also helps to caramelize the onions slightly, enhancing their sweetness. Add the sliced onions to the skillet and cook them until they become soft and translucent, which should take about 10-15 minutes. Stir occasionally to prevent them from browning too quickly. As the onions cook, season them with 1 teaspoon of salt, 1 teaspoon of garlic powder, and ½ teaspoon of dried oregano. These seasonings will infuse the onions with flavor, making each bite of the casserole irresistibly delicious.
3. Assemble the Casserole:
Once the onions are perfectly tender, it’s time to layer your casserole. Take a greased 9×13 inch baking dish and spread half of the sautéed onions in an even layer on the bottom. This base layer sets the stage for the cheesy layers that follow. Next, sprinkle half of the shredded Italian blend cheese, cheddar cheese, and Parmesan cheese over the onions. The combination of these cheeses provides a rich, creamy texture with a hint of sharpness from the Parmesan. Repeat the process with the remaining onions and cheeses, ensuring that the final layer is generously topped with cheese.
4. Bake the Casserole:
Now, it’s time to let the oven work its magic. Place the assembled casserole in the preheated oven and bake for 25-30 minutes, or until the top is golden brown and the cheese is bubbly and melted. As it bakes, the cheese will melt into the onions, creating a rich, gooey texture that’s hard to resist. The top layer of cheese will develop a slight crust, adding a delightful contrast to the soft onions underneath.
5. Cool and Serve:
Once the casserole is done baking, remove it from the oven and allow it to cool for a few minutes before serving. This resting time helps the casserole set, making it easier to slice and serve. You can garnish the casserole with fresh herbs like parsley or thyme for a pop of color and an added layer of flavor. Serve this dish hot, and watch as it quickly becomes the star of your meal.
Serving Suggestions
This Tennessee Onion Casserole is incredibly versatile and pairs well with a variety of main dishes. It’s a perfect side dish for roasted meats, grilled chicken, or even a simple salad. The rich, cheesy flavors complement savory dishes, adding depth and a touch of indulgence. If you’re hosting a holiday meal, this casserole makes a great addition to the spread, offering a comforting, homey dish that guests will love.
For those following a vegetarian diet, this casserole can serve as a main dish when paired with a side of crusty bread and a fresh green salad. The combination of onions and cheese is hearty enough to satisfy, making it a great option for Meatless Mondays or any day you’re looking for a lighter, yet satisfying meal.
Cooking Tips
- Onion Variations: If you want to experiment with different flavors, try using a mix of onions, such as red onions or yellow onions, alongside the sweet onions. Red onions will add a slight sharpness and a beautiful color contrast, while yellow onions offer a stronger, more traditional onion flavor.
- Cheese Options: While the recipe calls for an Italian blend, cheddar, and Parmesan, you can easily swap these out for other cheeses depending on your preference. Gouda, Gruyère, or even a bit of blue cheese can add a unique twist to the dish.
- Make-Ahead Option: This casserole is also a great make-ahead dish. You can prepare it up to a day in advance, refrigerate it, and then bake it just before serving. This makes it an excellent choice for busy holiday preparations or when you want to have something ready to pop in the oven.
The Cheesy and Delicious Tennessee Onion Casserole is a true comfort food classic that’s sure to become a favorite in your recipe collection. Its simplicity, combined with the rich flavors of caramelized onions and melted cheese, make it a go-to dish for any occasion. Whether you’re serving it as a side dish at a family dinner or bringing it to a potluck, it’s guaranteed to impress. With easy preparation, versatile serving options, and the ability to customize it to your liking, this casserole is a must-try for anyone who loves a good, cheesy dish. Enjoy the flavors of Tennessee with this warm, comforting, and utterly delicious onion casserole
