In medium bowl, combine eggs, milk and garlic salt; beat well. Set aside.
Melt margarine in large skillet over medium heat. Add ham, bell pepper and onion; cook and stir 2-4 minutes or until vegetables are crisp-tender.
Pour egg mixture over ham mixture in skillet. Cook until eggs are set but slightly moist, stirring occasionally from outside edge to center of pan. Remove from heat. Sprinkle with cheese. Cover; let stand 1 minute or until cheese is melted.