Heat 10-inch nonstick skillet over high heat. Reduce heat to medium-high. Add ham; cook 2 to 3 minutes, stirring frequently, until lightly browned. Remove ham from skillet; cover to keep warm.
To same skillet, place potatoes, onions, bell pepper and 1/2 cup of the milk. Heat to boiling. Reduce heat to medium; cover tightly and simmer 5 to 6 minutes or just until potatoes are tender.
Meanwhile, in small bowl, mix eggs and egg whites, the remaining 1/4 cup milk, the salt and pepper until well blended. Stir ham and egg mixture into potato mixture. Reduce heat to medium-low; cover and cook without stirring for 10 minutes.
Remove skillet from heat; remove cover (eggs will not appear completely cooked). Sprinkle cheese over top. Let stand 2 to 3 minutes or until egg mixture is set and cheese is melted. Cut into wedges to serve.