Heat oven to 375° Grease a large rectangular baking dish, 11x7x1-1/2 inches. (This makes a crust about 2-inches thick. Better to use a larger dish.) In a large bowl, mix baking mix with all dry ingredients. Add milk and eggs and mix with fork until batter is uniform color (batter will be lumpy). Stir in pepperoni, 1 cup cheese, the green pepper, onion; spread evenly in pan. Bake until top is light brown, about 30 minutes. (Crust may be made ahead and set aside at this point.) Spread crust with pizza sauce; sprinkle with mushrooms and remaining cheese. Bake just until cheese is melted, 1 to 2 minutes longer. 6 large servings, many appetizer servings. appet 47 10/10/92: Kribs, Salgarolos, Beste, Wafler