1¾ pounds boneless pork shoulder (or other 75% lean pork cut), diced into 1-inch cubes
13 ounces boneless pork loin, diced into 1-inch cubes
⅓ cup medium diced (½-inch) bacon
2¼ teaspoons fine sea salt, plus more as needed
1 tablespoon plus ¾ teaspoon ice water
1½ teaspoons finely chopped fresh mint
1½ teaspoons finely chopped fresh basil
1½ teaspoons minced lemongrass (from the bottom 3 inches of a stalk)
1½ teaspoons finely chopped fresh cilantro
1½ teaspoons peeled and minced galangal
1½ teaspoons minced shallot
1½ teaspoons minced garlic
1 teaspoon fish sauce
¾ teaspoon minced Makrut (kaffir) lime leaves
¾ teaspoon minced Thai chile
Freshly ground black pepper
Hog casings (about 8 feet)
Vegetable oil, for cooking
Butter, for basting
1. Place the pork shoulder, pork loin and bacon on a rimmed baking sheet and chill in the freezer until crunchy on the exterior but not frozen solid, about 1½ hours.
2. In a medium bowl, mix together the salt, ice water, mint, basil, lemongrass, cilantro, galangal, shallot, garlic, fish sauce, lime leaf and Thai chile until combined.
3. Nest a large empty mixing bowl in a bowl filled with ice and a little water. Using the small die of a meat grinder, grind the pork and bacon into the bowl set on ice.
4. Add the spice mixture to the ground pork and stir with your hands until well incorporated; the mixture should become homogenous and begin sticking to the side of the bowl.
5. Spoon 2 tablespoons of the meat mixture into a nonstick frying pan and spread into a thin patty. Cook the test patty over low heat until no longer pink. Taste the sausage, adding more salt and pepper as needed to the raw ground meat mixture. Cook a second test patty if needed.
6. Remove the bowl with the ground meat mixture from the ice bath. Press a sheet of parchment paper or plastic wrap directly on the surface of the meat to prevent oxidation, then cover the bowl tightly with another piece of plastic wrap and refrigerate overnight.
7. Rinse the hog casings well in cold running water to remove the salt. Place in a bowl and cover with cold water. Refrigerate overnight.
8. The next day, stuff the sausages into the casings: hold one end of a piece of hog casing up to the sink faucet nozzle and support it with your other hand. Gently turn on the water and let it run through the casings to rinse them and check for holes. (If there are any holes in the casings, cut out the pieces with holes.) Hold the casings in a bowl of cold water and refrigerate until ready to use.
9. Load the sausage mixture into a sausage stuffer, compressing it gently to remove air bubbles. Have ready a sausage pricker (a pin works, too) and a bowl of water. Moisten the nozzle of the sausage stuffer with water, and then load the casings onto the nozzle, keeping them straight and taking care not to double them up. Crank or turn on the stuffer and, when the meat just starts to come out of the nozzle, stop stuffing. Pull 4 to 5 inches of casing off the end of the nozzle but don't knot it. Moisten your work surface with water to prevent the sausages from sticking. With one hand, crank or turn on the sausage stuffer. Once the sausage mixture starts to fill the casing, remove the air by pinching and tying a knot at the end of the casing. Keep your free hand on the casing as the sausage fills. (If you see air pockets, prick the casing with the pricker (or pin). If the casing splits, cut the damaged bit of casing and discard. Reserve the sausage mixture that burst and add it back to the stuffer. Once stuffed, knot the end of the sausage rope.
10. Pinch the sausage about 6 inches from the end to make your first link and twist the link forward and around for about seven rotations. Form the second link; this time, pinch firmly and twist it backward. Repeat this process, alternating forward and backward, until you reach the open end of the casing. Twist the open end right at the last bit of filling to seal off the whole coil, and then tie a knot. It's best to refrigerate the links overnight before cooking.
11. To cook, separate the links from one another by cutting them where you twisted the casings. Set a large heavy skillet over medium heat and add a film of oil. When the pan is hot, add the sausages and brown on all sides. Once browned, add a few tablespoons of butter to the pan and continue to cook, basting the sausages with the hot fat to help them cook on all sides, until an instant-read thermometer reads 145° when inserted into the thickest part, about 30-35 minutes total. (Do not cut into them to determine doneness.) Alternatively you can cook them on a grill, first over direct heat until browned, then move them to more indirect heat until cooked through.