In A Large Skillet, Saute The Onions In Butter. In A Bowl, Lightly Beat Eggs And Milk; Pour Over The Onions. Cook Over Medium Heat; As The Eggs Set, Lift Edges, Letting Uncooked Portion Flow Underneath. When The Eggs Are Nearly Set, Sprinkle With The Corned Beef, Cheese And Pepper. Remove From The Heat; Cover And Let Stand For 1-2 Minutes Or Until The Cheese Is Melted. Cut Into Wedges.