Pasta with watercress and radish pesto

Method

1. Put the radish leaves and half the watercress and any thick watercress stalks in a food processor. Add the pumpkin seeds, cheese, garlic, lemon zest and juice. Whizz to a paste, then tip in half the sliced radishes. Pour in the oil, season with salt and pepper, then pulse until the radishes are finely chopped.
2. Cook the pasta in boiling salted water according to the packet instructions until al dente, adding the peas for the final 1 minute of cooking. Reserve a cupful of cooking water. Drain and return the pasta and peas to the pan, then stir in the pesto, adding enough of the cooking water to loosen so it coats the pasta. Divide among plates and top with the rest of the radish slices and watercress.