Mix ground chuck, egg, seasoning salt, chopped onion, bread crumbs, ketsup together. Take one medium head of cabbage and put under hot water and let it run over the cabbage until the leaves come off easily. Prepare a large pot of hot water, and let it simmer to a rolling boil. Put the cabbage leaves in the hot water for a few minutes until they are soft. Drain, and let cool. Roll the meat mixture in the long part of the cabbage leaf and fix it together with a toothpick. Brush top of rolls with butter pats, and wrap with bacon. Put into a large baking dish (enamel is preferable) and bake at 180ºC for about half hour until brown. Pour tomato sauce, which has been mixed with oregano, garlic, onion flakes and salt, over the rolls. Canned, crushed tomatoes and paste may also be used. Bake at 180ºC for about 1 hour, or until bacon is brown.