1. Combine mustard and mayonnaise in a small bowl. Spread 3/4 teaspoon of the mustard/mayonnaise mixture over four bread slices; layer each slice with 1 1/2 ounces ham and 1/4 cup cheese. Sprinkle evenly with pepper. Spread 3/4 teaspoon of the mustard/mayonnaise mixture over each remaining bread slice and place on top of the rest to create the sandwich.

2. Combine egg substitute and fat-free milk in a shallow dish. Dip both sides of each sandwich into the egg mixture.

3. Heat a large non-stick griddle or skillet over medium heat. Coat pan with cooking spray. Add sandwiches to pan; cook 3 minutes on each side or until lightly browned and cheese melts.