Ingredients:
4 red onions, thinly sliced
1/2 cup brown sugar
2 Tbsp. maple syrup
1/4 cup balsamic vinegar
1 package puff pastry, thawed at room temperature 397 gms
1 cup grated mozzarella cheese
1 cup Gorgonzola or Asiago cheese, grated
2 Tbsp. oil
1 egg yolk, beaten with some water
1 baking sheet, lightly greased
Method:
1. Preheat oven to 325°F. In a large bowl, combine the sugars, balsamic vinegar, onions, salt and oil. Toss and stir to coat the onions with this mixture.
2. Spread onions evenly on a baking sheet and tent the top with foil. Bake in the oven until onions caramelized and golden in color, about 1/1/2-2 hours. Remove from oven to cool, and reset oven temperature to 400°F.
3. Roll out puff pastry into a rectangle and place on baking sheet. Using a knife, score a 1-inch border and crimp the edges to form a decorative pattern. Brush the outside edges of the pastry with egg wash. Cover the pastry with onions, up to the decorative border. Mix the cheeses in a bowl and sprinkle generously on top over the onions.
4. Bake in 400°F oven until pastry is puffed and golden brown about 20-25 minutes. Cut into wedges or squares and serve warm.
