Sometimes the appetizer can be the star of the show of your holiday feast, and these mushroom bites are proof! Take a bite out of the savory, puff pastry goodness, and see for yourself why this simple mushroom appetizer is the way to go.

Instructions:

1. Preheat the oven to 400°F, and line a baking sheet with parchment paper.
2. Heat 1 tablespoon each of oil and butter on medium heat in a large cast-iron skillet. Once heated, add the mushrooms, and cook for about 5 minutes. Remove, and set aside.
3. Combine the remaining oil and butter in the same skillet, and add the onions. Cook until sautéed. Add the thyme and sugar, and cook for 25 minutes on medium-low heat, continually stirring.
4. Add the balsamic vinegar to deglaze the pan, allowing the onions to soak in the excess juices—and turn off the heat.
5. Put the onions in the mushroom mixture. Season with garlic powder, salt, and pepper, and stir. Wait until the mixture is at room temperature before proceeding.
6. Add the Gouda, Gruyère, and bacon bits. Mix well. Using a knife or a pizza cutter, cut the puff pastry into 1½-inch squares, and place them on the lined baking sheet. Make sure the puff pastry squares are cold before continuing. If not, put them in the refrigerator for 10–15 minutes.
7. Brush the lightly beaten egg onto the squares with a pastry brush. Add a tablespoon of the mushroom mixture to the center of each square. Bake for 20–25 minutes, rotating the pan halfway until the bites are crisp. Make sure they’re cool before serving.