For the sauce: Heat the tomatoes with 4 to 6 cups of water (enough o cover them) and boil until completely cooked. Remove from the heat and let cool a little. Get rid of the water and process in a blender or food processor. Pour the sauce back into the pot the tomatoes were cooked in a season with the rest of the dry oregano and salt, to taste. Add two cups of the broth from the lamb to the sauce.