There’s something extremely decadent about these tiny puffs of pastry, cremini mushrooms, gruyere cheese and a drizzle of truffle oil. Yet, they take no time to make and have so few ingredients. With that said, I encourage you to splurge on a couple really quality items.
Really good gruyere cheese is nutty and salty and perfect for this snack. Don’t skimp with any old waxy swiss (no offence to swiss cheese or people). Second, Dufour frozen puff pastry is all the rage right now and is worth the chatter. Finally, truffle oil is now a specialty staple in my house. A tiny drizzle will elevate any simple popcorn, mac and cheese, mushroom puff, anything… These three can all be found at The Fresh Market and will make this simple puff the most popular appetizer at your party. Invest now, or ask Santa for them on Christmas.
- 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
- 1/4 teaspoon ground black pepper
- 1/2 cup shredded Gruyere cheese
- 2, 10-inch square sheets frozen puff pastry, thawed
- 3 tablespoons dijion mustard
- Truffle oil, optional garnish
Preheat oven to 400 degrees F. Line two large baking sheets with silicone baking mats or parchment paper.
In a large skillet over medium low heat, heat 1 tablespoon olive oil and add the onions and salt. Sauté the onions until beginning to brown, then reduce heat to low and continue to cook, stirring occasionally, until deeply golden and caramelized, about 25 minutes total. Remove the onions to a large bowl and set aside.
In the same skillet, heat the remaining tablespoon olive oil over medium low and sauté the mushrooms until tender, about 5 minutes. Add garlic, thyme, and black pepper and sauté 1 additional minute. Place in the bowl with the onions.
On a lightly floured work surface, roll out the puff pastry into an even 10.5-inch square. With a 2-inch round cookie or biscuit cutter, cut the pastry into rounds. Transfer the cut puff pastry to a prepared baking sheet. Prick each round with a fork to allow air to escape, then top each round with a scant 1/4 teaspoon of mustard, then 1 tablespoon of the mushroom and onion filling, then sprinkle with cheese.
Bake for 25 minutes, until the pastry is golden and crisp. Garnish with more fresh thyme and a drizzle of truffle oil.