Brown 2 tablespoons finely chopped onion in butter or margarine over direct high flame.
Add 1 medium tomato, diced, and 3/4 teaspoon oregano; heat.
Reduce milk to 1/4 cup and add egg mixture to tomatoes.
Just before serving, sprinkle 1/2 to 3/4 cup shredded mozzarella or cheddar cheese and 1 teaspoon minced parsley over top.
Cover pan and allow cheese to soften.