In large skillet cook bacon till crisp; drain off drippings and crumble. Wipe pan clean. Cook scallions in butter over medium heat for 2 to 3 minutes. Add mushrooms and cook for 2 to 3 minutes more. Remove from heat. In bowl beat together the eggs, milk and pepper. Stir in cheese and the mushroom mixture. Pour into a greased 2-quart 12"x7"x2" baking dish. Bake at 350? for 35 to 40 minutes, or until puffed and knife inserted comes out clean. Let stand 5 to 10 minutes before cutting. Makes 6 servings