Breakfast sausage is simply fresh pork that has been ground and seasoned. It is available in three forms: patties, links, and bulk.
Because it is fresh pork, sausage must be cooked well done. This does not mean, however, that it should be cooked until it is just hard, dry, shrunken little nuggets, as it often is.
Most kitchens cook sausages by the same methods as bacon. For volume service, sausage is partially cooked in the oven and then finished to order. Link sausages hold better than patties because the links are protected from drying by their casings.