Tennessee Onion Casserole

This Tennessee Onion Casserole is a rich, cheesy, and savory dish that transforms simple sweet Vidalia onions into a warm, comforting side.

Baked with butter, garlic, and a blend of melty cheeses, this casserole delivers deep flavor with minimal effort. The natural sweetness of the onions caramelizes as they bake, perfectly balancing the salty, cheesy topping.

Whether served as a holiday side dish, a cookout companion, or a comforting appetizer, this easy-to-make casserole is sure to be a crowd-pleaser!

Why You’ll Love This Recipe:

Rich, Buttery, and Cheesy Flavor – The combination of sweet Vidalia onions, melted butter, and three kinds of cheese creates an indulgent, savory dish with a perfect balance of flavors.

Easy to Make – With just a few simple ingredients and minimal prep, this casserole is a fuss-free dish that bakes beautifully in under 40 minutes.

Caramelized Sweetness – As the onions bake, they soften and develop a natural caramelized sweetness that pairs perfectly with the melted cheese.

Versatile Side Dish – This casserole can be served alongside grilled meats, barbecue, roasted chicken, or even as a tasty appetizer with crusty bread or crackers.

Crowd-Pleaser – Whether it’s for a holiday gathering, potluck, or family dinner, this comforting and cheesy dish is guaranteed to be a hit with guests.

Gluten-Free & Low Carb – Naturally gluten-free and low in carbs, this dish is a great option for those looking for a hearty, satisfying recipe without added flour or starch.

Key Ingredients:

Sweet Vidalia Onions – The heart of the dish! These onions have a naturally mild and sweet flavor that caramelizes beautifully when baked.

Butter – Adds richness and depth, helping the onions soften and develop a melt-in-your-mouth texture.

Garlic Powder & Oregano – Brings a warm, savory aroma and a hint of earthy, herby flavor to complement the sweetness of the onions.

Italian Blend Cheese – A mix of mozzarella, provolone, and Parmesan that melts smoothly and creates a gooey, cheesy topping.

Cheddar Cheese – Adds sharpness and bold flavor, balancing the sweetness of the onions.

Parmesan Cheese – The final touch that gives the dish a crispy, golden-brown topping with a nutty, salty kick.

Salt & Black Pepper – Simple but essential for enhancing the natural flavors of the dish.

Tennessee Onion Casserole

Ingredients:

3 to 4 Sweet Vidalia onions

4 tbsp butter, sliced into small pieces

1 tsp salt

1 tsp garlic powder

½ tsp oregano

1 cup shredded Italian blend cheese

1 cup shredded cheddar cheese

½ cup shredded Parmesan cheese

Instructions:

Preheat & Prepare Dish:

Preheat your oven to 350°F (175°C).

Lightly coat a 9×13-inch baking dish with nonstick spray to prevent sticking.

Prepare the Onions:

Slice the onions into ¼-inch thick rings and separate them into individual rings.

Evenly distribute the onion rings across the prepared baking dish.

Season the Onions:

Sprinkle garlic powder, salt, and oregano over the onion rings for added flavor.

Add Butter & Cheese:

Place the butter slices evenly across the onions to enhance richness.

Sprinkle the Italian blend cheese and cheddar cheese over the entire dish.

Finish with a layer of Parmesan cheese for extra depth and crispiness.

Bake to Perfection:

Bake uncovered for 35-40 minutes, or until the cheese is melted, bubbly, and golden brown on top.

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Serve & Enjoy:

Let the casserole cool slightly before serving. Serve warm as a side dish or a flavorful appetizer.

Notes:

Use Sweet Vidalia Onions for the Best Flavor – Their natural sweetness balances the rich, cheesy topping. If Vidalia onions aren’t available, try using Walla Walla, Texas Sweet, or Maui onions for a similar taste.

Slice Onions Evenly – Cutting the onions into ¼-inch thick rings ensures they cook evenly and soften properly without turning mushy.

Customize the Cheese Blend – While the recipe calls for Italian blend, cheddar, and Parmesan, you can experiment with Gruyère, Monterey Jack, or mozzarella for different flavors.

Want Extra Crunch? – Sprinkle breadcrumbs or crushed crackers on top before baking for a crispy, golden topping.

Adjust the Seasoning – For extra flavor, add a pinch of paprika, cayenne, or smoked salt to enhance the savory notes.

Make It Ahead – This casserole can be assembled a day in advance, covered, and stored in the fridge. Simply bake when ready to serve!

Reheating & Storage – Store leftovers in an airtight container in the fridge for up to 3 days. Reheat in the oven at 350°F for 10-15 minutes to maintain texture.

Great for Pairing – This dish pairs wonderfully with grilled meats, barbecue, roasted chicken, or even as a dip with crusty bread!

Nutrition Information:

YIELDS: 8 | SERVING SIZE 1

Frequently Asked Questions:

Can I use different types of onions in this recipe?

Yes, you can experiment with different onion varieties, but the flavor and texture might vary. Vidalia onions are sweet and mild, but you could try using other sweet onion varieties for a similar taste.

Can I adjust the level of seasoning in the casserole?

Absolutely! You can adjust the amounts of salt, garlic powder, and oregano to suit your taste preferences.

Feel free to reduce or increase these seasonings as desired.

Can I use a different cheese blend or type of cheese for this casserole?

Of course! While the recipe suggests an Italian blend, you can use other types of cheese that you enjoy.

Experiment with different cheeses like mozzarella, provolone, or even pepper jack for unique flavors.

Can I prepare the casserole in advance and reheat it later?

Yes, you can assemble the casserole ahead of time and refrigerate it.

When ready to serve, you can bake it in the preheated oven until the cheese bubbles and browns.

Just keep in mind that the texture might differ slightly after reheating.

What can I serve alongside this casserole?

The casserole can be a versatile side dish. It pairs well with grilled meats, roasted vegetables, or a simple green salad.

You can also enjoy it with a slice of crusty bread or as a topping for a baked potato.

Can I use a different type of baking dish for this casserole?

Yes, you can use a different baking dish size or shape, but keep in mind that it might affect the cooking time and thickness of the casserole.

Adjust the baking time accordingly and monitor the cheese topping for the desired level of browning.

How can I make this casserole vegetarian or lighter?

To make this casserole vegetarian, you can skip the chicken and focus on the cheese and onion layers.

For a lighter version, you might consider reducing the amount of butter or using a butter substitute, and choosing reduced-fat cheese options.

Can I add other vegetables or ingredients to the casserole?

Certainly! You can customize the casserole by adding other vegetables like bell peppers, mushrooms, or spinach between the layers of onions and cheese.

Just make sure to adjust the seasoning accordingly.

Can I make this casserole gluten-free?

Yes, you can make this casserole gluten-free by ensuring that the cheeses and butter used are gluten-free.

You can also substitute gluten-free breadcrumbs or a gluten-free flour blend for the onion layers, if desired.

Can I make a smaller portion of this casserole?

Absolutely! You can halve the recipe to make a smaller portion.

Use a smaller baking dish and adjust the baking time accordingly, as the casserole may cook faster due to the reduced volume.