In A Large Skillet, Brown Sausage, Onion And Garlic; Drain. Remove From The Heat; Stir In Spinach And Mushrooms. Add Mozzarella Cheese, Salt, Pepper And Parmesan Cheese If Desired; Mix Well And Set Aside. Separate Crescent Dough Into Eight Rectangles; Seal Perforations And Flatten Slightly To 5-In. X 4-1/2-In. Rectangles. Place About 1/3 Cup Sausage Mixture On Half Of Each Rectangle To Within 1/2 In. Of Edges. Beat Egg And Water; Brush On Edges Of Dough. Bring Unfilled Half Of Dough Over Filling; Press Edges With A Fork To Seal. Brush Tops With Egg Mixture. Sprinkle The Cornmeal On A Greased Baking Sheet; Place Pockets On Baking Sheet. Bake At 350 Degrees F For 15-20 Minutes Or Until Golden Brown.