Whizz 300g of the peas with the soft cheese, lemon zest and juice, and the garlic. Add some seasoning, then set aside.
Meanwhile, cook pasta following pack instructions. Tip in the remaining peas 2 mins before the pasta is cooked, then drain everything and return to the pan. Stir through the pea pesto until warm and add some seasoning. Divide between 4 plates and serve with the prawns and extra lemon wedges, if you like.