1½ pounds pork butt, fat and sinew trimmed and cut into 1-inch cubes
2 tablespoons maple syrup
3 tablespoons water
2 garlic cloves, roughly chopped
1½-inch piece fresh ginger, peeled (use the edge of a teaspoon to scrape off the skin) and grated
1 tablespoon kosher salt
2 tablespoons finely chopped fresh sage leaves
1½ teaspoons ground mustard
¾ teaspoon ground fennel seed
¼ teaspoon cayenne
½ teaspoon freshly ground black pepper
⅔ cup ice water
Canola or grapeseed oil
1. Place the pork on a parchment-paper-lined rimmed baking sheet and freeze until the pork is stiff but not completely frozen, about 45 minutes. Also place the bowl and blade of a food processor in the freezer for 20 minutes to chill. Place the food-processor bowl on the base, add the meat and process, stopping the mixer every 10 seconds to redistribute the meat and remove any chunky bits of fat, until the meat is roughly chopped, about 30 seconds. Remove the blade from the bowl, clean and dry it, then place it in the freezer. Place the food-processor bowl filled with meat in the refrigerator.
2. In a small saucepan set over medium heat, bring the maple syrup, water, garlic, ginger and salt to a simmer. Simmer until the mixture has reduced by about half, about 5 minutes. Transfer the maple mixture to a small bowl and refrigerate until chilled.
3. In a small bowl, mix together the sage, ground mustard, ground fennel, cayenne and black pepper. Return the food-processor bowl filled with pork to the machine base. Fit with the freezer-chilled blade, add the chilled maple mixture, spices and ice water, and pulse in 5- to 8-second bursts to thoroughly blend the mixture (bits of ice in the meat mixture are fine). Scrape the sausage mixture into a medium bowl.
4. Set an 18-inch-long piece of plastic wrap on the counter. Take about a quarter of the sausage mixture, place it in the center of the plastic wrap and shape it into a 14-inch-long strip. Enclose it in plastic and roll to make a long, ½- to ¾-inch-wide rope. Hold the ends of the plastic wrap and twist them taut, then use them as handles to roll the rope back and forth against the counter, compacting the sausage and making the plastic wrap extra-tight. Place on a baking sheet and repeat with more plastic wrap and the remaining sausage mixture. Refrigerate for at least 30 minutes (or up to 3 days, or freeze for up to 3 months).
5. Remove a rope of sausage from the refrigerator and slice into 3-inch-long links (you will get about 6 links per rope). Unwrap each of the links and discard the plastic wrap. In a medium nonstick skillet set over medium-high heat, add 2 teaspoons oil. Heat until hot, then add the links to the pan. Reduce the heat to medium and cook on all sides until golden-brown and the sausage is cooked through, about 8 minutes total. Transfer to a paper-towel-lined plate to cool slightly before serving.