Bring stock to a low boil, add the sauerkraut juice. Mix the sour cream, flour, and egg. Add some of the boiling stock-juice to the pot and simmer for 4 minutes. Add the mashed potatoes and sprinkle in the dill. Cook for 3 more minutes. Serve in bowls and sprinkle the croutons liberally. ORIGIN: Lissa Dwornikov, Liev-Ukraine, circa 1996 per Don Houston