In a 10-inch skillet melt margarine or butter. Meanwhile, in a bowl beat together eggs and milk. Stir in ham. Pour egg mixture into skillet. Cook, without stirring, over medium heat until mixture begins to set on the bottom and around the edges. Using a large spoon or spatula, lift and fold partially cooked eggs so uncooked portion flows underneath. Continue cooking and stirring over medium heat about 4 minutes or until eggs are cooked throughout but are still glossy and moist. Remove from heat.
Spread top halves of croissants with some salad dressing. Sprinkle cheese over bottom halves. Spoon egg mixture onto cheese-topped croissants. Add croissant tops. Makes 4 servings.