Spray a 10-inch ovenproof skillet with nonstick spray coating. Prepare skillet over medium heat. Add ham, onion, and green pepper. Cook about 4 minutes or until vegetables are tender and ham is lightly browned.
Meanwhile, in a mixing bowl combine eggs, cottage cheese, and black pepper. Pour over ham mixture in skillet.
Cook over medium-low heat. As egg mixture sets, run a spatula around the edge of the skillet, lifting egg mixture so uncooked portions to flows underneath. Continue cooking and lifting edges until egg mixture is almost set (surface will be moist).
Place skillet under broiler 5 inches from heat. Broil for 1 to 2 minutes or until eggs are set.
Arrange tomato slices on top of frittata. Sprinkle cheddar cheese over tomato. Broil 1 minute more.