Saute onions in butter till golden.
Core and steam cabbage periodically peeling off leaves when tender. Save small leaves and any extra to chop
Mix the meat ingredients together. Don't over mix. Using a large disher, which holds about 1/2 cup or 1/4# of the mixture to form a log. Roll the log up in a cabbage leaf, tucking in the sides.
Place the rolled cabbage in a large greased vessel. This can be a large roasting pan, Dutch oven, or other pot or pan that can hold the cabbage and sauce.
Optionally add a jar of sauerkraut or two to your own taste
Mix the sauce ingredients together thinning with sauerkraut liquid and water to taste, pour over the rolled cabbage.
Cover and place in an oven preheated to 350 degrees. Cook till a temperature probe placed in the centermost rolled cabbage registers about 170 F.
NOTE do NOT cover directly with tin foil. The foil will dissolve when in contact with the tomato sauce. Place some parchment paper or other non-metallic substance between the foil and the tomato sauce.