Place first 4 ingredients on a double layer of cheesecloth. Gather edges of cheesecloth together; tie securely.
Trim fat from lamb shank. Place cheesecloth bag, lamb, and next 11 ingredients (lamb through crushed red pepper) in a large Dutch oven. Bring to a boil; reduce heat, and simmer, uncovered, 2 hours or until lamb is tender. Discard cheesecloth bag. Remove lamb shank from soup. Remove lamb from bone, and discard bone. Cut meat into bite-size pieces, and stir meat into soup. Spoon into shallow bowls, and sprinkle each serving with 1 teaspoon mint and 1 teaspoon vinegar.