1 (16-ounce) jar sliced pickled beets, liquid reserved and, if desired, beets coarsely chopped
1/2 cup chopped fresh dill
Accompaniment: sour cream
Directions
Bring borscht, broth, tomato sauce, and onion to a boil over high heat in a 4- to 5-quart heavy pot.
Meanwhile, coarsely shred duck meat, discarding skin and bones.
Stir coleslaw, caraway seeds, salt, pepper, cloves, duck meat, reserved liquid from pickled beets, and half of dill into borscht mixture. Return to a boil, then reduce heat and simmer, covered, until onion is tender, about 15 minutes.
Stir in pickled beets and simmer until heated through. Discard cloves if desired, then serve soup with sour cream and remaining dill.