You can leave the sausages whole, but if you cut them up into 1 pieces, it is easier to serve and eat and you dont need a knife. Fry the sausages in dutch oven-type pan in hot olive oil until browned. (They will almost be cooked through at this point and will finish in the crock pot.) Remove the sausage to a crock pot. Add a little oil to the pan if necessary and dump in the onions and peppers. Quickly brown them for a few minutes then add them to the crock pot with the sausage. Add canned tomatoes if desired. Pour in the marinara sauce. You may need more or less than the one jar, depending on how saucy you prefer. Add the Italian seasonings and any other seasonings you like. Mix this all up and put the crock pot on low for about 2-3 hours. This all can be made right in the dutch oven too. Just cover and simmer for 20 or 30 minutes or until done. * (Hot, Mild or both) cut into 1 pieces Each package has about five large links each. Low-fat turkey sausage is pretty good too, but drier.