Cook sausage in large nonstick skillet over medium heat 4-5 minutes or until hot. Stir in potatoes.
Beat eggs, cheese, salt and pepper in large bowl with wire whisk. Pour over sausage mixture.
Cook over medium-high heat 2 minutes, occasionally lifting edge with spatula and tilting skillet to allow uncooked egg to flow underneath. (Do not stir.)
Reduce heat to medium-low; cover. Cook 14-17 minutes or until eggs are set.
Top with tomato and onions. Cut into 8 wedges to serve.