Bring a large pot of generously salted water to the boil for the pasta.
Heat a wide heavy frying pan over medium heat. Toast the fennel seeds in the dry pan for 30 seconds until aromatic. Add the olive oil, then the garlic and chilli flakes. Cook 1 minute.
Add the sausage meat in chunks. Do not move for 90 seconds, then break up with a wooden spoon. Cook 6 to 8 minutes until deeply browned with a layer of fond on the pan.
Pour in the white wine, scraping the fond. Reduce by half, about 2 minutes.
Add the crushed tomatoes. Season with salt and pepper. Simmer 10 minutes while the pasta cooks.
Cook the pasta in the boiling water for 1 minute less than packet directions. Reserve 1 cup of pasta water before draining.
Drain the pasta, transfer to the sauce. Add a quarter cup of pasta water and the pecorino. Toss vigorously over medium heat for 1 minute until the sauce clings glossily.
Serve immediately in warm bowls, scattered with extra pecorino, torn fresh basil and a final twist of black pepper.