Description

Tennessee Onions is a savory baked casserole featuring layers of sweet Vidalia onions seasoned with a blend of spices and topped with a trio of melted cheeses. This comforting dish combines the natural sweetness of onions with sharp cheddar, smoky Gouda, and Parmesan, finished with butter and fresh parsley to create a rich and flavorful side perfect for any occasion.

Ingredients

Scale

Vegetables

3 pounds Vidalia or sweet onions (about 4 large), cut crosswise into 1/4-inch-thick slices

Seasonings

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)

Cheeses

4 ounces mild cheddar cheese, shredded (about 1 cup), divided
4 ounces smoked Gouda or cheddar cheese, shredded (about 1 cup), divided
1 1/4 ounces grated Parmesan cheese (about 1/3 cup store-bought grated)

Others

4 tablespoons (1/2 stick) unsalted butter, diced
Cooking spray
2 tablespoons finely chopped fresh parsley leaves, for garnish (optional)

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Instructions

Prepare the oven and onions: Preheat your oven to 350ºF. Lightly coat a 9×13-inch baking dish with cooking spray to prevent sticking. Separate the sliced Vidalia onions into rings and place them in a large mixing bowl. Add kosher salt, dry mustard powder, garlic powder, smoked paprika, and cayenne pepper, then toss thoroughly to evenly coat the onions with the seasonings.
Layer the first half of onions and cheeses: Arrange half of the seasoned onion rings in an even layer at the bottom of the prepared baking dish. Sprinkle evenly with half of the shredded mild cheddar and smoked Gouda cheeses, about 2 ounces each, to create a rich cheese layer.
Add remaining onions and cheese toppings: Layer the remaining onion rings on top of the cheese. Then, sprinkle with the remaining shredded cheddar and smoked Gouda cheeses. Evenly distribute the grated Parmesan cheese over the top and scatter the diced unsalted butter pieces on the surface to add flavor and richness as it bakes.
Bake the casserole: Cover the baking dish tightly with aluminum foil to trap moisture. Bake for about 45 minutes, or until the onions become tender and the casserole begins to bubble. Remove the foil and continue baking for an additional 30 minutes, allowing the cheese on top to melt fully and develop browned, bubbly spots, indicating a perfectly caramelized finish.
Garnish and serve: Once baked, optionally sprinkle the casserole with fresh chopped parsley for a touch of color and fresh flavor. Serve warm as a comforting side dish.

Notes

Use Vidalia or other sweet onions for the best flavor and natural sweetness.
Adjust the cayenne pepper amount according to your heat preference or omit if you want a milder dish.
For added flavor variation, substitute smoked Gouda with sharp white cheddar if preferred.
This dish pairs beautifully with grilled meats or roasted poultry.
Use fresh grated Parmesan for better melting and flavor compared to pre-grated varieties.