Prepare your ingredients by gathering all items and washing and chopping parsley for garnish.
Cook the sausage in a frying pan over high heat, breaking it up into crumbles until golden brown.
Sauté shallots and fennel seeds in the pan until shallots soften.
Boil a large pot of water for the pasta, using slightly less water than usual.
Cook the pasta until al dente, reserving about 500ml of pasta water before draining.
Combine flavors by adding lemon zest, chili flakes, and garlic to the sausage mixture.
Finish the dish by adding pasta, reserved pasta water, crème fraîche, and Parmesan, tossing until creamy.