Cheeseburger Soup

1 pound ground beef
¾ cup chopped onion
¾ cup shredded carrots
¾ cup diced celery
3 cups chicken broth
2 cups diced peeled potatoes
3 tablespoons all-purpose flour
3 tablespoons butter
2 cups (8 ounces) sharp cheddar cheese
1-1/2 cups milk
1 teaspoon salt
½ teaspoon peppe

INSTRUCTIONS