In a large stockpot, combine the carrots, parsnip, beets, apple, leek, bay leaves, allspice, garlic, vinegar, lemon juice, salt, and sugar. Top with 10 cups of water.
Cover the pot and bring to a boil. Once boiling, reduce heat and simmer for about an hour.
Remove vegetables from broth. Add dumplings and cook according to package directions.
Serve hot, garnished with parsley and a dollop of sour cream.