Cheddar Cheese Soup

3 Tbs  butter
1 medium onion, finely chopped
1 shallot, finely chopped
1 medium carrot, finely chopped
1 stalk celery, finely chopped
1 clove garlic, finely chopped
2 Tbs  all-purpose flour
3 cups  chicken stock
2 cups  half-and-half
3 Tbs  dry sherry (optional)
Salt and freshly ground pepper to taste
Cayenne pepper to taste (optional)
12 oz  sharp cheddar cheese, shredded
Chopped fresh chives for garnish (optional)

Heat the butter in a large soup pot over moderate heat and saute the
chopped vegetables until tender but not brown, about 5 minutes.  Stir
in the flour and cook, stirring frequently, for 2 minutes.  Whisk in
the chicken stock and half-and-half and bring to a boil.  Reduce the
heat and simmer for 3 minutes.  Remove from the heat and stir in the
optional sherry, salt, pepper, and optional cayenne.  Add the cheese a
little at a time, whisking constantly until the cheese has melted.
Serve immediately, garnished with chopped chives if desired.  Note:
When reheating leftovers, bring the soup barely to a simmer over low
heat.  Do not boil as the cheese will separate.  Serves 4 to 6.