Spread one side of each slice of bread with 1 teaspoon of margarine.
Heat a medium-sized skillet over medium heat . Coat with nonstick cooking spray. Add the egg substitute and cook for 1 minute without stirring. Using a spatula, lift up the edges so that the uncooked portion gets underneath. Cook for an additional 1-2 minutes or until eggs are nearly set and begin to puff up. Flip over and cook for 30 seconds.
Remove the egg mixture from the heat and put half the eggs on the unbuttered sides of two of the slices of bread. Put even amounts of cheese over the eggs and then top with the remaining slices of bread, buttered side out.
Put the skillet back on medium heat and allow it to get hot. Coat with nonstick cooking spray and add the two sandwiches. Cook for 3 minutes on one side, then flip and cook on the other side for 2 minutes or until golden. Cut each sandwich in half and serve.