Brown beef; drain and add mushrooms, 1.5 cups cheddar and onion. Remove from heat and set aside. Combine bisquick and water to form a soft dough. Add remaining cheese, mixing in well. Pat into a greased 13X9 inch baking dish, spreading halfway up sides.
Spread meat mixture over dough and sprinkle with broccoli. Combine remaining ingredients and pour over top. Bake at 350 until a knife inserted in center tests clean, about 35 minutes. To make Spinach Beef Pie: use spinach in place of broccoli and Swiss cheese in place of Cheddar. Taste of Home Ground Beef Collection 1996 Edition