Combine the pork, pork fatback, sugar, garlic, fennel seeds and 1 tablespoon salt in a large bowl. Transfer to a large plastic zip-top bag and refrigerate overnight.
At least 30 minutes before grinding the meat, place all of your tools (including the meat grinder parts, stand mixer bowl, stand mixer paddle attachment and sausage stuffer parts) in the freezer to chill.
Using your meat grinder, grind the marinated meat mixture through the small die plate into the chilled bowl of the stand mixer. Refrigerate at least 30 minutes, then return the mixture to the mixer and beat on medium speed using the chilled paddle attachment, 1 to 2 minutes. Refrigerate until ready to use.
Stuff the sausages and, for best results, refrigerate overnight. Before cooking, pierce each sausage several times with a pin. Grill over medium heat until the center registers 150 degrees F, 10 to 12 minutes. (You can also pan-fry or broil the sausages.) Serve with coleslaw.