Place the chicken stock, wine, cabbage, beets and onion in a large pot. Bring to a boil, reduce heat and simmer until vegetables are tender, for about 30 minutes, stirring occasionally. Add the vinegar, cumin, salt and pepper. (This can be prepared ahead, cooled, covered and set aside at cool room temperature for several hours or refrigerated for several days.) To serve, remove from the refrigerator for about 30 minutes before serving if presenting chilled. Simmer over medium-high heat to reheat if presenting warm. Ladle into 4 soup bowls. Spoon on a generous dollop of yogurt. Serve immediately.