Mushroom and Caramelized Onion Puff Pastry Bites Recipe
These Mushroom Puff Pastry Bites are savory, flaky appetizers featuring caramelized onions, sautéed baby bella mushrooms, fresh thyme, and melted Gruyere cheese atop buttery puff pastry rounds. Perfectly baked until golden and crisp, they make an elegant and delicious finger food for parties or special occasions.
- Prep Time: 15 minutes
- Cook Time: 35 minutes
- Total Time: 50 minutes
- Yield: 50 bites 1x
- Category: Appetizer
- Method: Baking
- Cuisine: American
Ingredients
Scale
Mushroom and Onion Filling
- 2 tablespoons extra virgin olive oil (divided)
- 1 large yellow onion, thinly sliced
- 1/2 teaspoon kosher salt
- 16 ounces baby bella mushrooms, sliced
- 1/2 teaspoon minced garlic
- 2 teaspoons finely chopped fresh thyme leaves (or 1/2 teaspoon dried)
- 1/4 teaspoon ground black pepper
- 1/2 cup shredded Gruyere or Swiss cheese (about 1 1/2 ounces)
Puff Pastry and Topping
- 2 sheets frozen puff pastry, 10-inch squares, thawed
- 1 egg, beaten
- 3 tablespoons whole-grain mustard
- Chopped fresh parsley, for garnish
Instructions
- Preheat: Place oven racks in the upper and lower thirds of the oven and preheat to 400°F (200°C). Line two large baking sheets with silicone mats or parchment paper and set aside.
- Caramelize Onions: In a large skillet over medium-low heat, warm 1 tablespoon olive oil. Add sliced onions and kosher salt. Sauté, stirring occasionally, until onions begin to brown. Reduce heat to low and continue cooking, stirring occasionally, until onions are deeply golden and caramelized, about 25 minutes. Transfer onions to a large bowl.
- Sauté Mushrooms: Using the same skillet, heat the remaining 1 tablespoon olive oil over medium-low heat. Add sliced mushrooms and cook until tender, about 5 minutes. Stir in minced garlic, thyme, and black pepper and cook for an additional minute. Add the mushroom mixture to the bowl with the caramelized onions. Stir in the shredded Gruyere cheese.
- Prepare Puff Pastry: On a lightly floured surface, roll each puff pastry sheet into an even 10.5-inch square. Using a 2-inch round cookie or biscuit cutter, cut the pastry into rounds (about 25 rounds per sheet). Alternatively, cut into squares to minimize waste.
- Assemble Bites: Place the pastry rounds onto the prepared baking sheets. Lightly brush each round with beaten egg. Prick each round with a fork to let air escape. Spread approximately 1/4 teaspoon whole-grain mustard on each round, then top with 1 tablespoon of the mushroom and onion filling. Repeat for all rounds and the second pastry sheet.
- Bake: Bake for 25 minutes, or until puff pastry is golden and crisp. Halfway through baking, rotate pans 180 degrees and switch positions of the baking sheets between the upper and lower racks for even cooking.
- Serve: Let the bites cool for 5 minutes after baking. Garnish with chopped fresh parsley. Serve warm or at room temperature.
Notes
- Thaw puff pastry according to package instructions before starting.
- Use a light hand with the mustard to avoid overpowering the mushroom flavor.
- Fresh thyme is preferred for best flavor but dried thyme works as a substitute.
- Gruyere can be substituted with Swiss or a similar melting cheese.
- You can prepare the mushroom filling a day ahead and refrigerate.
- These bites are best served the same day but can be reheated gently in the oven.
Keywords: Mushroom appetizers, puff pastry bites, caramelized onion, Gruyere cheese, party snacks, vegetarian appetizers
