Tomato and Cheese Risotto

Ingredients

• tomatoes

  diced
  2 medium
• butter or margarine

  divided
  2 tablespoons
• chopped onion
  ½ cup
• uncooked U.S. arborio or medium-grain rice
  1 cup
• dry white wine
  ⅓ cup
• chicken broth

  divided
  2 cups
• water
  3 cups
• shredded mozzarella cheese
  ½ cup
• shredded Swiss cheese
  ¼ cup
• grated Parmesan cheese
  ¼ cup
• milk
  ¼ cup
• salt and ground black pepper
  1 unit