Cauliflower Cheese Soup

1/4 cup water
2 cups milk
1/2 cup shredded carrots
1/4 cup chopped onion
2 - 10 3/4 ounc cans of cream of potato soup, undiluted
1 - 7 ounce whole kernel corn, drained
1 1/2 cups fresh frozen cauliflower florets, cooked until tender
1 cup shredded Cheddar cheese
1/2 cup shredded provolone or mozzarella cheese
2 tablespoons butter
1/8 teaspoon pepper

In a saucepan, heat water, butter, carrots and onion until carrots are tender. Stir in soup, milk, corn and cauliflower. Heat through. Just before serving, stir in the cheeses and pepper.