Heat oven to 350°. Brown hamburger and onion. Drain fat. Add taco seasoning mix and water. Simmer 10 minutes. Scoop 2 tablespoons mixture and 1 tablespoon refried beans on each tortilla. Fold and place in a 9x13-inch baking dish. Pour tomatoes with green chilies over tortillas. Cover with cheese and cover with foil. Bake for 45 minutes. Yields 10 servings.