Melt 1 teaspoon margarine in a large nonstick skillet over medium heat. Add turkey ham, and cook 1 minute on each side or until lightly browned. Remove from skillet; set aside, and keep warm.
Melt remaining 1 teaspoon margarine in skillet over medium heat. Add egg substitute; cook 45 seconds or until set, stirring occasionally. Place 1 cheese slice on each of 4 muffin halves. Divide egg substitute mixture evenly among sandwiches, and top with turkey ham and remaining muffin halves.