Using a small knife, trim round the broccoli to remove the dark green florets from the main stalks and put them to one side. Peel the stalks, trim off the dry end and throw this away. Peel and chop the garlic.
Finely chop the broccoli stalk and put into a large pan with the garlic, anchovies and half the butter. Crumble in the chilli, cover with a lid and cook slowly for 8 to 10 minutes while you cook the pasta in boiling salted water according to the packet instructions.
Something I like to do which is slightly different (but better, I’d like to think) is to cook the broccoli florets with the pasta for the last 4 minutes – this makes them soft enough to eat but leaves them with great colour and texture.
Drain the pasta and broccoli, saving a little of the cooking water, then toss into the other pan. Remove the pan from the heat.
Season to taste with sea salt, black pepper, the rest of the butter and finely grate in a large handful of Parmesan. Mix well, adding a little of the cooking water, to loosen, if needed, and make it shine.
Serve immediately, sprinkling with another good handful of finely grated Parmesan.