How to Make It
Heat butter in a saucepan over medium heat. Add onion and carrot; cook 10 minutes. Stir in chestnuts, thyme, ginger, and allspice; cook 1 minute. Add apple brandy; cook until reduced by half. Combine chicken stock and flour; stir with a whisk. Add stock mixture and 1 cup water to pan. Bring to a boil; reduce heat, cover, and simmer 12 minutes. Place mixture in a blender. Blend until smooth. Return to pan; cook over low heat 3 minutes. Stir in salt, vinegar, and pepper.