In a large pot, melt butter. Add carrots, celery, onion, green pepper, mushrooms
and ham. Cook over medium heat until vegetables are tender.
Add some of the chicken stock to the flour and cornstarch. Stir to blend. Add
broth to the pot and stir in the flour mixture. Stir until thickened. Add the
cayenne pepper, salt and pepper. Stir in milk, add cheese and do not let boil
once the cheese and milk are in the pot or it will curdle.