Step 1: Prepare the Aromatic Base : Heat olive oil in a large heavy-bottomed pot or Dutch oven over medium heat. Add the chopped onion, fennel, carrot, and celery. Sauté for about 8–10 minutes, until softened and lightly golden. Stir in the minced garlic and fennel seeds; cook for 1 minute until fragrant.
Step 2: Brown the Pork :Add the ground pork to the pot. Break it apart with a wooden spoon and cook for 8–10 minutes, until browned all over. Season generously with salt and pepper.
Step 3: Deglaze and Build the Sauce :Pour in the wine and let it simmer for 2–3 minutes, scraping up any brown bits from the bottom. Stir in the tomato paste, crushed tomatoes, broth, oregano, chili flakes, and bay leaf.
Step 4: Simmer the Ragu :Bring the mixture to a boil, then reduce the heat to low. Cover partially and simmer gently for 2 hours, stirring occasionally. The sauce should thicken and the pork should become very tender. Add a splash of broth or water if it gets too thick.
Step 5: Finish the Ragu : Once the sauce is rich and silky, stir in a splash of milk or cream to mellow the acidity. Adjust seasoning with salt and pepper.
Step 6: Cook the Pasta :Bring a large pot of salted water to a boil. Cook pappardelle according to package directions until al dente. Reserve ½ cup of pasta water, then drain the rest.
Step 7: Combine and Serve : Add the cooked pasta to the ragu. Toss gently, adding a bit of pasta water to coat evenly. Serve immediately, topped with grated Parmesan, chopped fennel fronds, and a drizzle of olive oil.