1Place 3 pounds chopped top rib of beef (or beef shin) in a large soup pot. Cover with 2 quarts chicken stock and 1 quart cold water and bring to a boil. Reduce the heat to low, skim as necessary, and simmer 1 hour.
2Add 2 cups chopped onions; 1 tablespoon chopped garlic; 1 (2 1/2 to 3 pound) green cabbage, cored and shredded; 1 15-ounce can chopped plum tomatoes; and 1 tablespoon ground caraway. Bring back to a boil, then reduce heat again and simmer 2 hours, covered.
3Remove the beef from the soup. Cool and then pick the meat from the bones, discarding the bones, fat, and any connective tissue. Shred the beef and add it back to the soup along with 1/4 cup fresh lemon juice and 2 tablespoons dark brown sugar. Season to taste with salt and pepper.
4Cool and then refrigerate the soup overnight. The next day, remove and discard the hardened fat from the top of the soup. Reheat, seasoning if necessary with a little more salt, lemon juice, and sugar.