This is good "basic" recipe, but it needs the addition of FENNEL Seed and RED PEPPER Flakes to make it "Italian Hot Sausage".
To make the sausage, you will need a meat grinder with a sausage stuffing attachment or "horn". Assemble meat grinder and prepare the casings: Choose long pieces of the casings so that you have more control over the size of the links that you wish to make. Soak the casings in cool water about 5 minutes (more soaking will make the casings very tender and prone to bursting) about an hour in advance of stuffing to remove the salt on the outer surface. Rinse under cool running water. To remove excess salt from the inside, hold one end of a casing in place on a faucet nozzle and turn on cold tap water to fill the casing with liquid. If you spot any holes in the casing at this time, discard or cut the damaged bit off. Remove from faucet and squeeze out water; cover the rinsed and drained casings and refrigerate until ready to use. Fill the casings and make links by twisting the sausage two or three turns at the points where you wish them to be (a 4-inch link is a good snack or lunch size, but smaller ones make good hors d'oeuvres). Carefully place the sausages in a large saucepan or Dutch over. Cover with reserved 2 cups stock, adding water if necessary to cover. Heat over high heat until water reaches 180F (just below a simmer, keeping at that temperature to prevent the sausages from bursting) and continue cooking until the sausage is heated through and the flavors blend, 15 to 20 minutes. Drain and let rest about 15 minutes before slicing; serve immediately.