For the sauce, in a small mixing bowl, combine the tomato soup and diced tomatoes. Set the bowl aside until needed.
In a large mixing bowl, with a large spoon, combine the mushroom soup, tomato soup, pork, beef, onions, and seasonings. Once the mixture is thoroughly combined, prepare the baking dish. In a glass, 9 by 13-inch pan, pour about 2/3 of the reserved tomato sauce in the bottom the pan. Set the remaining 1/3 aside.
To stuff the cabbage leaves, place about 3 ounces of the meat mixture on each leaf. Then tightly roll the mixture into the leaf. Place each roll, as they are finished, into the prepared baking dish. When all of the cabbage rolls are in the pan, spread the remaining third of the tomato sauce on top of them. Cover the dish with aluminum foil and bake in the oven for 60 to 75 minutes, until the cabbage rolls are cooked through. Serve.