Spaghetti with shrimp and pesto

Place the pasta in a pan of boiling water, add the salt, and cook for about 4 minutes. While the pasta is boiling, heat a frying pan, add a knob of butter, a chopped clove of garlic, chopped parsley and fry a little, adding more butter if necessary. Then cook the peeled prawns - fry over a moderate heat for two minutes on each side. Drain the pasta, transfer to a bowl, add the pesto and mix well. Layer the prawns, halved tomatoes, and grate the cheese over the top. Garnish with greens.