This is a great appetizer for Sunday's football game! We've been enjoying these amazingly tasty bites for a few years now and I generally like to keep some in the freezer to pop in the oven.
Buy your puff pastry today, thaw it in the refrigerator and tomorrow you can have these put together and tucked into the freezer to bake on Sunday!
- 1/4 cup butter
- 3 - 4 cups sliced button mushrooms
- 1 large onion or 2 medium, sliced thin
- 1 tablespoon sugar
- 2 tablespoons balsamic vinegar
- 1/4 teaspoon thyme
- salt and pepper to taste
- about 1 cup shredded cheese (your choice, swiss, mozzarella or gruyere)
- 1 package puff pastry, thawed but cold *
- 1 egg, beaten
- Melt butter in a large fry pan, and add the mushrooms and onion. Stir occasionally over medium heat until the the vegetables are tender.
- Add, the sugar, balsamic vinegar, and thyme. Continue to fry until the onions and mushrooms have caramelized and the liquids have reduced. Season with salt and pepper and set aside to cool to room temperature. Add the cheese and combine.
- If using the block of puff pastry, roll it out to about an 1/8 inch. I roll mine to about 14 X 14
- Cut a thin border around the rectangle to clean up the edges and then cut the rectangle into approximately 1 1/2 - 2 inch squares. A pizza wheel works great for this.
- Brush each square with beaten egg and then drop a heaping teaspoon of onion, mushroom mixture onto the center of each square. Arrange on a lined cookie sheet and freeze before putting into freezer bags or refrigerate until ready to bake. (within a day)
- Preheat oven to 400. Bake for about 20 minutes or until golden brown. Do not open the oven while the pastry is puffing but once they are beginning to brown, rotate pans if necessary.
* In Canada, puff pastry is available in a 397 gram block and I purchase Tenderflake. Look for it by the frozen pie shells. In the US you can buy it already in sheets, and I believe it would be about a pound so you would just thaw and proceed with step #4. Since the sizes vary, you may get a few more made out of the US box. Do not be afraid to thaw, prepare and then refreeze. I've been making these for several years and they still bake up beautifully. Just be sure to keep the pastry cold and bake it when it is cold!
Makes about 3 dozen