Here is simple,
Throw some cheap hamburger in a bowl, add some spices, black pepper, salt, chop an onion throw it in, add some minute rice.
Take a large head of cabbage, remove the core, bring to boil, remove from water and allow to cool. Unfold the cabbage leaves, place your mixed hamburger/rice in cabbage leave and fold.
Line your crockpot with leaves before you start stacking the rolls. Pierce rolls with fork, stack in crockpot and you can add either tomatoe soup, tomotoe juice or stewed tomatoes for liquid.
Made a batch last week for a Polish Christmas Eve dinner but because their were several Polish people in their late 70's I used a combination of hamburger, veal and pork sausage.