If you love the rich flavors of Southern cooking and crave a comforting dish that’s perfect for Lunch, this Tennessee onions recipe is a must-try. Layers of sweet, tender onions baked with gooey cheese and aromatic spices make this casserole irresistible. Whether you serve it as a side dish or enjoy it as the centerpiece of a casual meal, this recipe is full of Southern charm and savory indulgence.
Why You’ll Love Tennessee Onions
There are plenty of reasons to make this dish a regular on your lunch menu:
- Extra cheesy layers: The combination of mild cheddar, smoked Gouda, and a sprinkling of Parmesan creates a luscious, melty texture that elevates simple onions into a decadent casserole.
- Sweet, tender onions: Vidalia onions—or any sweet onion variety—are naturally mild and caramelize beautifully when baked, giving each bite a perfect balance of sweet and savory.
- Easy to assemble: Minimal chopping is required, and the layering process is straightforward, making this a stress-free Lunch recipe.
- Versatile: Serve it as a side dish for grilled meats, or enjoy it on toasted bread for a hearty vegetarian Lunch option.
- Make ahead: This casserole can be prepared in advance and baked just before serving, making it convenient for meal prep or hosting.
Ingredients for Tennessee Onions
To make this recipe, you’ll need the following ingredients:
- Cooking spray, for greasing the baking dish
- 3 pounds (about 4 large) Vidalia or sweet onions, sliced crosswise into 1/4-inch-thick rings
- 1 1/2 teaspoons kosher salt
- 1 teaspoon dry mustard powder
- 1 teaspoon garlic powder
- 1 teaspoon smoked paprika
- 1/4 teaspoon cayenne pepper (optional, for a slight kick)
- 4 ounces (1 cup) mild cheddar cheese, shredded, divided
- 4 ounces (1 cup) smoked Gouda or cheddar cheese, shredded, divided
- 1 1/4 ounces (1/3 cup) grated Parmesan cheese
- 4 tablespoons (1/2 stick) unsalted butter, diced
- 2 tablespoons finely chopped fresh parsley leaves, for garnish (optional)
Pro Tip: Vidalia onions are preferred for their natural sweetness, but any mild onion variety works well for this recipe.
How to Make Tennessee Onions
Step 1: Prepare the Oven and Dish
Preheat your oven to 350°F (175°C). Lightly coat a 9×13-inch baking dish with cooking spray to prevent sticking. This will ensure your onions and cheese bake evenly without sticking to the dish.
Step 2: Prep the Onions and Seasoning
Separate the sliced onions into individual rings and place them in a large mixing bowl. Add kosher salt, dry mustard powder, garlic powder, smoked paprika, and cayenne pepper. Toss everything together gently so that each onion ring is evenly coated with the flavorful spices. This step is crucial for infusing the onions with a well-rounded savory taste.
Step 3: Layer the Casserole
Arrange half of the seasoned onion rings evenly in the prepared baking dish. Sprinkle 2 ounces of shredded mild cheddar and 2 ounces of smoked Gouda over the onions. This first layer of cheese begins building the rich, melty texture that makes this casserole so irresistible.
Next, layer the remaining onions on top, spreading them evenly. Sprinkle with the remaining 2 ounces each of cheddar and smoked Gouda. Finish with grated Parmesan cheese for a golden, slightly nutty topping. Scatter the diced butter evenly over the top to help the cheese brown and the onions caramelize during baking.
Step 4: Bake Covered
Cover the dish with aluminum foil to trap moisture and allow the onions to soften. Bake for approximately 45 minutes, until the onions are tender and the casserole is bubbling. This ensures that the onions are fully cooked but retain their shape and sweetness.
Step 5: Uncover and Brown
Remove the foil and continue baking for 30 minutes, or until the cheese on top is melted, golden, and slightly browned in spots. This final step gives the casserole a beautiful presentation and adds extra flavor through the caramelization of the cheese and onions.
Step 6: Garnish and Serve
Before serving, sprinkle the casserole with fresh chopped parsley for a pop of color and added freshness. Serve hot as a savory Lunch dish alongside crusty bread, roasted meats, or a fresh green salad.
Tips for Perfect Tennessee Onions
- Even slicing: Consistent onion slices ensure even cooking and uniform layers.
- Use fresh cheese: Freshly shredded cheese melts better and creates a gooier texture.
- Adjust spices: Modify the cayenne pepper for a milder or spicier casserole depending on your preference.
- Make ahead: You can assemble the casserole up to a day in advance. Cover and refrigerate until ready to bake.
- Storage: Leftovers keep well in an airtight container in the refrigerator for up to 4 days. Reheat gently in the oven to retain the cheese’s creamy texture.
Serving Suggestions
- As a Lunch: Enjoy a hearty portion with toasted bread, avocado slices, or a side salad for a filling midday meal.
- Side Dish: Pair with grilled chicken, pork chops, or baked fish for a Southern-inspired dinner.
- Vegetarian Option: Serve as the main component of a meatless Lunch or dinner alongside roasted vegetables or grains.
