My Mom,German (the Germans from Russia that were under Catherine the Great and moved to the Dakotas)always made them with cooked rice. Her recipe (which I now have) also has ground pork in them along with the hamburger. I cut a circle on top of the cabbage and cut out part of the spine; somewhat of a top shape, so the leaves just basically fall off; then pick them out of the water with tongs. No apples in my recipe but the meat is laid on a bit of sauerkraut. I also lay halved or quartered potatoes on top of the rolls the last 45 minutes of cooking; they get nicely steamed.