Bring a large saucepan of lightly salted water to the boil. Add the cauliflower and when the water comes back to the boil, cook for 5 or 10 minutes, or until the cauliflower has softened. Transfer it to a bowl with a slotted spoon and leave it aside. Reserve the water to cook the pasta.
Heat the olive oil in a large saucepan and add the garlic, half the parsley and the anchovy fillets.