Description
Tennessee Onions is a savory casserole featuring sweet Vidalia onions layered with a blend of mild cheddar, smoked Gouda, and Parmesan cheeses, seasoned with spices and baked to bubbling perfection. This comforting southern-style dish combines tender, flavorful onions with a rich cheesy topping, perfect as a hearty side or a flavorful vegetarian main.
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)
Other
- Cooking spray
- 4 tablespoons (1/2 stick) unsalted butter, diced
- 2 tablespoons finely chopped fresh parsley leaves, for garnish (optional)
Instructions
- Prepare the onions and seasoning: Heat the oven to 350ºF. Lightly coat a 9×13-inch baking dish with cooking spray. Separate the 3 pounds of sliced Vidalia onions into rings and place them in a large bowl. Add 1 1/2 teaspoons kosher salt, 1 teaspoon dry mustard powder, 1 teaspoon garlic powder, 1 teaspoon smoked paprika, and 1/4 teaspoon cayenne pepper (if using). Toss well to evenly coat all onion rings with the seasoning.
- Layer the first half of onions and cheese: Arrange half of the seasoned onion rings in an even layer in the prepared baking dish. Sprinkle evenly with 2 ounces each of shredded mild cheddar and shredded smoked Gouda cheeses (about 1/2 cup of each).
- Add the remaining onions and top with cheeses and butter: Arrange the remaining onion rings on top of the first layer. Sprinkle with the remaining 2 ounces each of mild cheddar and smoked Gouda. Evenly sprinkle 1 1/4 ounces grated Parmesan cheese over the top. Scatter 4 tablespoons diced unsalted butter across the surface to add richness.
- Bake and finish: Cover the baking dish tightly with aluminum foil and bake in the preheated oven until the onions are softened and the casserole is bubbling, about 45 minutes. Remove the foil and bake uncovered for an additional 30 minutes, or until the cheese on top is melted and browned in spots. Remove from oven and, if desired, sprinkle 2 tablespoons finely chopped fresh parsley leaves over the casserole before serving.
Notes
- Vidalia or other sweet onions work best for a naturally sweet flavor; avoid sharper onion varieties.
- Cayenne pepper is optional and can be omitted if you prefer no heat.
- The cheeses can be substituted with other mild and smoked cheese blends based on preference.
- This casserole can be prepared ahead of time and baked just before serving.
- For a richer flavor, let the casserole rest for a few minutes after baking to allow flavors to meld.
- Leftovers keep well refrigerated for up to 3 days and reheat nicely.
- Prep Time: 20 minutes
- Cook Time: 1 hour 15 minutes
- Category: Side Dish
- Method: Baking
- Cuisine: Southern American
Nutrition
- Serving Size: 1 cup (about 1/8 of recipe)
- Calories: 210
- Sugar: 8g
- Sodium: 480mg
- Fat: 14g
- Saturated Fat: 7g
- Unsaturated Fat: 6g
- Trans Fat: 0.4g
- Carbohydrates: 17g
- Fiber: 2g
- Protein: 7g
- Cholesterol: 35mg
Keywords: Tennessee onions, Vidalia onions, onion casserole, baked onions, cheesy onion bake, southern side dish, vegetarian casserole
