Chestnut Soup

Ingredients

• 1 large head garlic
• 2 tsp. salt
• 1 small onion, cut up
• 1 lb. fresh chestnuts
• 1/2 stick butter
• 1 rib celery, cut up
• 1/8 tsp. crushed red pepper flakes
• 1/4 cup dry sherry
• 2 quarts chicken stock
• 2 bay leaves
• 4 sprigs flat-leaf parsley
• Pinch nutmeg
• 1 quart half-and-half