Cabbage Rolls with stuffing

1 head cabbage , center core removed 2 -3 tablespoons butter 1 cup chopped onion 1 lb ground beef 1 lb ground pork 1 lb ground veal 2 cups cooked white rice 1[...]

2 pounds ground beef lean 1/2 cup rice uncooked 1 medium onion diced 1 each green bell pepper diced 2 large eggs 1 each cabbage large head 2 quarts tomato[...]