Description
This Old-Fashioned Onion Casserole with Cheddar and Gouda is a comforting baked side dish featuring sweet onions layered with aromatic herbs and spices, topped with a rich blend of mild Cheddar and smoked Gouda cheeses, and baked to golden perfection. It’s perfect for cozy family dinners or holiday gatherings.
Ingredients
Ingredients
- Cooking spray, for greasing the dish
- 2 1/2 lb. sweet onions (about 3 large onions), sliced crosswise into 1/4-inch-thick slices and separated into rings
- 1 tsp. dried thyme
- 1 tsp. dried parsley flakes
- 1 tsp. garlic salt
- 1/2 tsp. dried oregano
- 1/2 tsp. dry mustard
- 1/4 tsp. cayenne pepper
- 1/4 cup salted butter, cut into 1/4-inch-thick pieces
- 4 oz. mild Cheddar cheese, shredded (about 1 cup)
- 4 oz. smoked Gouda cheese, shredded (about 1 cup)
Instructions
- Preheat Oven: Preheat your oven to 325°F (163°C) and lightly grease a baking dish with cooking spray to prevent sticking.
- Prepare Onions and Seasonings: Slice the sweet onions crosswise into 1/4-inch-thick rings and separate them. In a large bowl, toss the onion rings with dried thyme, parsley flakes, garlic salt, dried oregano, dry mustard, and cayenne pepper to evenly coat the onions with the spices.
- Arrange Onions in Dish: Transfer the seasoned onions to the prepared baking dish, layering them evenly to ensure consistent cooking.
- Add Butter and Cheese, then Bake Covered: Distribute the pieces of salted butter evenly over the onions. Sprinkle the shredded mild Cheddar and smoked Gouda cheeses on top. Cover the dish tightly with aluminum foil and bake in the preheated oven at 325°F for about 40 minutes, or until the onions are soft and the sides are bubbling.
- Uncover and Finish Baking: Remove the foil and increase the oven temperature to 350°F (177°C). Continue baking uncovered for an additional 30 minutes or until the top is golden brown and bubbly, ensuring a deliciously melted cheese crust.
Notes
- Use sweet onions for best flavor and natural sweetness in the casserole.
- Adjust cayenne pepper to your preferred spice level or omit for a milder dish.
- For a crispier top, you can broil the casserole for 2-3 minutes at the end, watching carefully to avoid burning.
- Leftovers can be refrigerated for up to 3 days and reheated in the oven.
- Feel free to substitute cheeses as desired, but keep similar melting cheeses for best results.
- Prep Time: 20 minutes
- Cook Time: 1 hour 5 minutes
- Category: Side Dish
- Method: Baking
- Cuisine: American
