Description
Delight in these Caramelized Onion & Gruyère Stuffed Mushrooms, a savory French-inspired appetizer featuring tender mushrooms filled with a rich mixture of caramelized onions, garlic, thyme, Gruyère, and a crispy breadcrumb topping. Perfectly baked to golden perfection, these stuffed mushrooms make an elegant party snack or appetizer that can be prepared ahead and baked just before serving.
Ingredients
Scale
Mushrooms and Filling
- 20 large white or cremini mushrooms, stems removed and finely chopped
- 2 tablespoons olive oil
- 1 large yellow onion, thinly sliced
- 2 tablespoons unsalted butter
- 2 garlic cloves, minced
- 1/4 teaspoon salt
- 1/4 teaspoon black pepper
- 1 teaspoon fresh thyme leaves (or 1/4 teaspoon dried)
- 1/2 cup grated Gruyère cheese
- 1/4 cup panko breadcrumbs
- 2 tablespoons grated Parmesan cheese
Garnish
- Chopped fresh parsley (optional)
Instructions
- Preheat and prepare baking sheet: Preheat your oven to 375°F (190°C) and line a baking sheet with parchment paper to prevent sticking and ensure easy cleanup.
- Caramelize the onions: In a large skillet, heat the olive oil over medium-low heat. Add the thinly sliced onion and cook slowly for 20–25 minutes, stirring frequently, until the onions become deeply golden and caramelized, developing a sweet and rich flavor.
- Sauté the filling ingredients: Add the unsalted butter, minced garlic, chopped mushroom stems, salt, black pepper, and thyme leaves to the caramelized onions. Continue sautéing for another 5–7 minutes until the mixture softens and becomes fragrant, blending all the flavors together.
- Combine the cheese and breadcrumbs: Remove the skillet from heat and let the mixture cool slightly. Then stir in the grated Gruyère cheese, panko breadcrumbs, and grated Parmesan cheese until well combined, forming a flavorful stuffing mixture.
- Stuff the mushrooms: Spoon the cheese and onion filling generously into each mushroom cap, ensuring they are well filled but not overflowing. Arrange the stuffed mushrooms evenly on the prepared baking sheet.
- Bake the mushrooms: Place the baking sheet in the preheated oven and bake for 18–20 minutes, or until the mushrooms are tender and the tops are golden brown and crispy.
- Garnish and serve: Remove the mushrooms from the oven, garnish with chopped fresh parsley if desired, and serve them warm as a delicious appetizer or party snack.
Notes
- These stuffed mushrooms make an elegant appetizer or party snack suitable for entertaining.
- You can prepare the filling and stuff the mushrooms ahead of time, then refrigerate them before baking to save time.
- For a different flavor profile, swap Gruyère cheese with sharp white cheddar or fontina cheese.
- Prep Time: 20 minutes
- Cook Time: 30 minutes
- Category: Appetizer
- Method: Baking
- Cuisine: French-Inspired
