Soak the beans overnight covered with cold water. Boil meat in 1 1/2 litres of cold water. Peel onions and add them to the meat with bay leaf, peppercorns and juniper berries. Cook for 1 1/2 hours over medium heat. Add the beans 45 minutes before the end of the cooking time. Clean, wash and quarter the cabbage, cut out the stalk.
Cut cabbage into pieces. Chop tomatoes in a tin and add them to the soup with cabbage and thyme. Cook for 10 minutes. Take out meat and cut into small cubes, put back into the soup. Season to taste with salt and pepper