Watercress and cob nut pesto

Wash the watercress and she’ll the nuts.

Peel the garlic and add the items to a blender with a little oil and the juice of a lemon. Whizz and scrape down the sides and whizz again. You can add more oil until you have the desired consistency.

Add the Parmesan, salt and the rind of the lemon (if it’s unwaxed) to taste.