In a bowl, combine salmon, mushrooms, pickle relish, rice, scallions, parsley, salt, and pepper.
Place 1 tablespoon of filling in the center of each square.
Brush inside edges of puff pastry with egg wash and fold over to make a triangle. Using a fork, seal the edges. Poke a slit or two in the top of each turnover.
Brush tops with egg wash.
Bake in oven for 30 minutes or until golden brown.