In A Small Skillet, Saute Mushrooms In Butter Until Tender; Drain. In A Bowl, Combine The Flour, Eggs, Milk And Pepper Until Smooth. Stir In 1 Cup Cheese, Bacon And Mushrooms. Pour Into A Greased 8-In. Square Baking Dish. Sprinkle With Remaining Cheese. Bake, Uncovered, At 375 Degrees F For 18-20 Minutes Or Until Eggs Are Completely Set.