BEAT eggs and milk in small bowl with fork until well blended. Add ham, onions and pepper; mix well.
POUR into 8-inch nonstick skillet sprayed with cooking spray; cover. Cook on medium heat 6 min. or until egg mixture is set but top is still moist.
SPRINKLE cheese onto half the omelet; fold in half. Remove from heat; let stand, covered, 1 min. Cut in half.