Best-Ever Potatoes

    7 cups coarsely chopped small red potatoes
    1 cup chopped onion
    1 8-ounce carton dairy sour cream
    1 cup (4 oz.) shredded Monterey Jack cheese
    1 cup (4 oz.) shredded sharp cheddar cheese
    1/2 teaspoon salt
    1/4 to 1/2 teaspoon ground red pepper
    2 medium tomatoes, seeded and chopped

In a large saucepan cook potatoes and chopped onion, covered,
in a small amount of boiling water for 12 to 15 minutes or until
tender; drain. Stir in sour cream, Monterey Jack cheese, cheddar
cheese, salt, and red pepper. Stir in chopped tomatoes. Spoon into
a 2-quart rectangular baking dish. Bake, uncovered, in a 350F oven
about 30 minutes or until heated through.