Leftover Roast Pork Shoulder Makes a Restaurant-Worthy Ragù

Name: Leftover Roast Pork Shoulder Makes a Restaurant-Worthy Ragù
Cuisine: European, Italian, Mediterranean
Ingredients: 2 tablespoons (30ml) rendered pork fat from roast pork shoulder or extra-virgin olive oil (see note); 1 medium yellow onion (about 8 ounces; 225g), finely chopped; 1 medium fennel bulb (about 10 ounces; 285g), cored and finely chopped, fronds reserved; 1 celery stalk (about 2 ounces; 55g), finely chopped; Kosher salt and freshly ground black pepper; 1 medium garlic clove (5g), minced; 2 teaspoons (4g) finely chopped fresh rosemary leaves; 1/2 cup (120ml) dry white wine; 4 cups (1L) homemade pork or chicken stock, or store-bought low sodium chicken stock (see note); 1 pound (450g) roast pork shoulder, pulled into 2-inch long pieces (see note); Reserved drippings from roast pork shoulder (optional); 1 pound (450g) homemade or store-bought fresh egg dough pasta such as pappardelle, tagliatelle, or maltagliati, or dried penne; 3 tablespoons (42g) unsalted butter; 2 tablespoons (30ml) fresh lemon juice from 1 lemon, plus 2 teaspoons finely grated zest; 2 ounces (55g) grated Parmigiano-Reggiano or Pecorino Romano