Heat a large saute pan, lightly coated with evoo, over medium heat. Caramelize onion until golden brown. Add mushrooms to pan and saute until golden brown.

Add garlic, paprika, and crushed red pepper flakes and continue sauteing for just a minute until garlic is fragrant. Season to taste with salt and pepper. Cool filling before proceeding.

Roll out dough just a bit to an even thickness. Cut 3-inch squares.

Place 1 tablespoon of filling in the center of each square. Fold square over to form a triangle. Crimp edges with a fork.

Chill bourekas for 30 minutes.

Preheat oven to 350°F. Line 2 baking sheets with parchment.

Whisk egg with 2 tablespoons of water. Brush each boureka with egg wash and sprinkle with sesame or poppy seeds.

Bake at 350°F for 25 to 30 minutes or until crispy and brown.