1/4 cup chopped onion
2 tablespoons olive oil
1 (6 ounce) can tomato paste
2 (16 ounce) cans whole peeled tomatoes with juice
1 cup shredded mozzarella cheese
1 cup shredded sharp Cheddar cheese
In a medium bowl, mix chopped onion, olive oil and tomato paste. Mix well and refrigerate until thoroughly chilled.
Place tomatoes into a medium saucepan with juice over medium heat. Cover and simmer until tomatoes are slightly softened and egg is cooked, about 5 minutes. Drain and stir in cheese. Heat through, stirring occasionally, until cheese mixture is thickened.