a few basil leaves, shredded with your fingers, plus extra for sprinkling
lemon wedges, for squeezing
Plunge the pasta into a large pan of salted boiling water and cook according to packet instructions until al dente. Drain the pasta into a colander and hold it under cold running water to cool it down quickly.
Shake off the excess water and tip the pasta into a large bowl. Toss in 1 tbsp olive oil to coat thoroughly (this helps stop the pasta from sticking together), then add the prawns.
Mix the pesto, mayonnaise and lemon or lime juice with some salt and pepper to taste. If you need to slacken the mixture a bit, stir in a little more olive oil. Pour the pesto dressing over the pasta and prawns and give everything a good stir. Add the parsley and basil leaves and stir again, then pile into your serving dish and serve scattered with extra shredded basil leaves, plus lemon wedges for squeezing over the salad.