Spaghetti with Walnut Rocket Pesto

Combine the walnuts, garlic, rocket and basil in a food processor or blender. Process just until they are coarsely chopped. While the machine is running, add the olive oil in a thin stream. Transfer the pesto to a bowl. (At this point the pesto can be frozen. Thaw before proceeding.)

Stir the Parmesan cheese, salt and cayenne into the pesto.

Cook pasta according to package instructions. Drain the pasta, return it to the empty pot, and toss it with the pesto, adding a tablespoon or two of water if necessary to distribute the pesto evenly.

Transfer the pasta to a serving bowl or to individual plates, garnish with additional Parmesan cheese and serve.