Beat eggs with water and soy sauce. Stir in bean sprouts, mushrooms and green onions; mix well.
Spray an 8 inch (20 cm) non stick skillet with cooking spray. Heat skillet over medium heat. Pour in one third of egg mixture. As mixture sets at the edges, with spatula, gently lift cooked portion to allow uncooked egg to flow underneath. Cook until bottom is set and top is almost set. Slide onto a plate. Invert back into skillet and cook completely for about 1 minute. Slide onto a warm plate.
Repeat procedure to make 2 more omelettes, stacking them.
Cut into wedges and serve with warm oriental sauce.
Heat together 2 tsp (10 mL) cornstarch, 1/2 cup (125 mL) beef broth and 1 tbsp (15 mL) soy sauce, stirring constantly; boil for 1 minute. Serve with Egg Foo Yung.
Preparation: 10 minutes
Cooking: 12 minutes