Place 4 whole prawns in a large non-stick frying pan with 1 tablespoon of olive oil, off the heat. Pull off the rest of the prawn heads and chuck them into the pan for bonus flavour. Quickly pull the legs and tails off the prawns and peel off the shells. Run the tip of your knife down their backs and pull out the vein, then chop the prawns.
Peel and finely slice the garlic. Put the frying pan on a medium-high heat and, after 2 minutes, stir in the garlic and chopped prawns, followed 1 minute later by the pesto, stirring regularly.
Meanwhile, cook the pasta in a pan of boiling salted water according to the packet instructions.
Pour the rosé into the prawn pan and let it bubble and reduce for 1 minute.
Drain the pasta, reserving a mugful of cooking water, then toss the pasta into the prawn pan, loosening with a little reserved cooking water, if needed.
Toss over the heat for 1 minute, then taste, season to perfection with sea salt and black pepper, and dish up.