Caramelized Onion & Gruyère Stuffed Mushrooms Recipe
These Caramelized Onion & Gruyère Stuffed Mushrooms are a delicious appetizer featuring tender mushrooms filled with a savory blend of sweet caramelized onions, creamy Gruyère cheese, and crunchy breadcrumbs, all baked until golden and bubbly. Perfect for parties or a flavorful snack.
- Prep Time: 20 minutes
- Cook Time: 20 minutes
- Total Time: 40 minutes
- Yield: 12 stuffed mushrooms 1x
- Category: Appetizer
- Method: Baking
- Cuisine: French-inspired
- Diet: Vegetarian
Ingredients
Scale
Mushroom Preparation
- 12 large white or cremini mushrooms, stems removed and reserved
- 1 tablespoon olive oil
Caramelized Onion Filling
- 1 medium onion, thinly sliced
- 2 tablespoons butter
- 1/2 teaspoon sugar
- 1/4 teaspoon salt
- 1/4 teaspoon black pepper
Cheese and Breadcrumb Mixture
- 1/2 cup grated Gruyère cheese
- 1/4 cup fresh breadcrumbs (preferably panko)
- 1/4 cup grated Parmesan cheese
- 1 tablespoon fresh thyme, chopped (optional)
Instructions
- Preheat Oven: Preheat the oven to 375°F (190°C). Line a baking sheet with parchment paper or lightly grease it to prevent sticking.
- Caramelize Onions: In a skillet, melt the butter over medium heat. Add the thinly sliced onions along with salt, pepper, and sugar. Cook, stirring occasionally, until the onions become soft, golden brown, and caramelized, about 15–20 minutes. Remove from heat and let cool slightly.
- Prepare Mushrooms: Brush the mushroom caps with olive oil and arrange them cavity side up on the prepared baking sheet.
- Make Filling: Finely chop the reserved mushroom stems and combine them in a bowl with the caramelized onions, grated Gruyère cheese, fresh breadcrumbs, and grated Parmesan cheese. Season the mixture with additional salt and pepper to taste, and mix well.
- Stuff Mushrooms: Spoon the onion and cheese filling into each mushroom cap, pressing gently to pack the mixture securely inside.
- Bake: Place the stuffed mushrooms in the preheated oven and bake for 15–20 minutes until the mushrooms are tender and the cheese on top is melted and golden brown.
- Garnish & Serve: Sprinkle with fresh thyme if desired and serve immediately for best flavor and texture.
Notes
- For extra richness, add a small amount of cream cheese or mascarpone to the filling.
- These mushrooms can be made ahead of time; refrigerate them unbaked and bake just before serving.
- Swap Gruyère cheese with other melting cheeses like Swiss or fontina for a different flavor profile.
Keywords: stuffed mushrooms, caramelized onion, Gruyère cheese, appetizer, baked mushrooms, party snacks, vegetarian appetizer
