Step 1 Cut away the bones and big pieces of rind from the pork and set aside, leaving the rind in pieces as large as possible. The bones will be used for stock (recipe below); the rind will be cooked with the meat.
Step 2 Cut the pork meat into roughly 11/2-inch cubes, including all of the fat, and set aside in a large mixing bowl. You should have about 3 3/4 pounds of cubed meat.
Step 3Grind together 2 tablespoons salt, pepper flakes, fennel seeds and 2 teaspoons black pepper. Sprinkle over the cubed meat and toss to coat evenly. Seal tightly and refrigerate at least 2 hours while you prepare the pork stock, or overnight.
Step 4When ready to cook, heat the oven to 250 degrees. Combine the spiced cubed pork and the rind in a large Dutch oven or lidded heavy pot with the smashed garlic. Pour over enough pork stock to just cover, about 2 cups. Bring to a simmer on top of the stove and skim any gray foam that rises to the top, then cover and place in the oven.
Step 5Cook until the meat is tender enough to smash between your fingers, about 2 1/2 hours.
Step 6Remove from the oven and let the meat cool in the broth for 20 minutes. Use a slotted spoon to remove the meat and rind from the broth. Transfer the meat to a large mixing bowl and set the rind aside. Pour the broth through a cheesecloth-lined strainer into a measuring cup.
Step 7When the meat is cool enough to handle, shred it by hand. The meat should not all be the same size, but all over the large pieces should be broken down. Chop the rind fine and add it to the meat.
Step 8Stirring vigorously with a wooden spoon, very slowly incorporate the white wine and then the strained pork stock. You'll wind up with a sticky, very soft mass. Season to taste with more salt, pepper flakes and black pepper.
Step 9Line a 9-by-5-inch loaf pan with plastic wrap, with plenty left over to hang over the sides. Pour the meat mixture into the loaf pan and thump the pan solidly on the work surface to even the meat and release any air bubbles. Fold the plastic wrap over the top, set another loaf pan on top of the meat and weight it with a couple of cans of food. Refrigerate at least 4 hours, preferably overnight. Alternatively, you can pack the meat into glass or earthenware crocks, cover with plastic, weight and refrigerate.
Step 1 0When ready to serve, use the excess plastic wrap as handles to lift the meat from the loaf pan. It will come out in one solid piece, like a terrine. If the terrine sticks, run a metal spatula or knife around the edges to loosen the plastic wrap from the pan. You can serve this either sliced as a terrine or in a crock as a spread alongside grilled or toasted bread.