Combine pork shoulder, fat back, and remaining ingredients, except casings, in a bowl and mix thoroughly. Cover and refrigerate several hours.
Rinse casings thoroughly in lukewarm water. Tie one end of a casing and stuff by pushing meat through a funnel inserted in the untied end; tie other end. Continue until all the meat and casings have been used.
Poach sausages in boiling water for 1 hour. Cool. Cut into slices and fry in a skillet until browned.
Note: If desired, omit casing, form sausage into patties, and fry until cooked.