From the same article about walnuts as the walnut soda bread recipe below.
Walnut and parsley pesto
Pesto is, of course, perfect with pasta, but I also serve this one as a sauce-cum-relish with grilled lamb chops or steak. Serves four.
1 fat garlic clove garlic, peeled and roughly chopped
100g hard, mature goat's cheese (or Parmesan), grated
50g flat-leaf parsley leaves
About 150ml good olive oil (or extra-virgin rapeseed oil)
Juice of ½ lemon
Sea salt and freshly ground black pepper
Put the walnuts and garlic into a food processor and process until finely chopped - but still with some granular texture. Add the cheese and process again briefly. Add the parsley and blitz again to chop the leaves, then begin trickling in the oil, while the processor runs. Stop when you have a sloppy purée. Taste, season as necessary with lemon juice, salt and pepper. If you don't have a food processor, you can make the pesto with a large pestle and mortar, crushing the ingredients together in the same order.
Store in the fridge - if you completely cover the surface of the pesto with oil so all air is excluded, it should keep for a couple of weeks.