Put abundant water on to boil for the pasta, waiting for it to come to the boil before salting it. Add the pasta and cook according to packet instructions, though start checking it a good two minutes before it’s meant to be ready.
While the pasta is cooking, make the sauce by putting all the remaining ingredients, bar the basil, into a processor and blitzing until you have a nubbly-textured sauce.
Just before draining the pasta, remove a cupful of pasta-cooking water and add two tablespoons of it down the full of the processor, pulsing as you go.
Tip the drained pasta into your warmed serving bowl, Pour and scrape the sauce on top, tossing to coat (add a little more pasta-cooking water if you need it) and strew with basil leaves.