In A 10-In. Nonstick Skillet, Melt 2 Tablespoons Butter Over Medium Heat. Add Ham And Potato; Cook And Stir Until Potato Is Lightly Browned. Stir In The Cheese, Milk, Horseradish And Bacon; Cook Until Cheese Is Melted. Remove And Keep Warm. In The Same Skillet, Met Remaining Butter. In A Bowl, Beat The Eggs, Water, Salt And Pepper. Pour Into Skillet; Cook Over Medium Heat. As Eggs Set, Lift The Edges, Letting Uncooked Portion Flow Underneath. When Eggs Are Nearly Set, Spoon Potato Mixture Over Half Of The Omelet. Fold Omelet Over Filling. Cover And Cook For 1-2 Minutes Or Until Heated Through.