In a slow cooker, mix the sauerkraut with the onion, chicken broth, wine, caraway seeds and bay leaf. Nestle the bockwursts, garlic sausage and bacon in the sauerkraut. Cover and cook on low heat for 3 hours, until the sauerkraut is flavorful and the bacon is tender. Add the ham steak, cover and cook until heated through, about 10 minutes. Discard the bay leaf. Spoon the choucroute into shallow bowls, sprinkle with the parsley and serve with mustard and steamed potatoes.