Perfect Umami Puffs

• Meat

  • 5 slices Bacon, thick cut

• Produce

  • 10 Crimini mushrooms
  • 2 Onions, large
  • 1 tsp Thyme, dried

• Refrigerated

  • 1 Egg

• Condiments

  • 1 Balsamic vinegar
  • 1 tsp Balsamic vinegar

• Bread & Baked Goods

  • 2 sheets Puff pastry

• Dairy

  • 1 tbsp Butter
  • 1 Parmesan cheese

Found on contemplatingsweets.com

Description

Directions

• Caramelize the onions: Thinly slice the onions and heat a large saucepan over medium-low heat. Melt the butter and add the sliced onions. Stir occasionally, and cook until onions are soft, caramelized, and a nice brown color. If frond is sticking to the bottom of the pan and wont come up with stirring, add a small splash of balsamic vinegar (or chicken stock or white wine), and deglaze the pan. Onions are done when they are very soft and sweet, about 40 minutes to an hour.
• Preheat oven to 425 degrees F. Take puff pastry out of freezer and set aside to thaw. Chop the bacon and cook over medium heat until crispy. Quarter (or cut into sixth for larger pieces) the mushrooms and saute in 1 T of left over bacon grease (or regular oil such as canola) over medium heat. When softened, add balsamic vinegar and dried thyme and stir, cooking for a minute or two longer. 
• When puff pastry is sufficiently defrosted, unfold and lay out on a cutting board. Cut each sheet into 6 squares. Taking a paring knife, cut another square inside each square, about 1/2 inch in from each side. We want to set the filling on the smaller square and have the sides puff up around it. Beat the egg with a splash of water and using a pastry brush, brush the egg wash onto the puff pastry (you can just do the outer portion since the middle will be covered with the onion mixture). Combine caramelized onions, bacon, and mushrooms in a bowl, and spoon onto the centers of each puff. 
• Bake in oven until lightly browned and puffed, about ten minutes. Remove from oven and grate parmesan cheese over each piece.