To prepare the pesto, put the almonds, garlic, basil and parmesan in a food processor and grind in some pepper. Add the olive oil and whizz until you have a smooth paste.
Cook the pasta in a large saucepan of lightly salted boiling water for 10–12 minutes, or according to the packet instructions, until al dente.
Pour 1½ tablespoons of the pasta cooking water into a heated serving dish, drain the pasta and tip into the dish. Add the pesto and toss gently to mix. Serve immediately, with some extra parmesan. If you like, scatter over some sprigs of fresh basil to garnish.
Nuts are best bought in small quantities and should be used soon after purchase to prevent them going rancid. Store in an airtight container in a cool place.