To make the pesto, blitz all the ingredients in a blender, adding further lemon to taste if needs be or oil for consistency. Set aside.
Place the cod fillets skin side down on a greased baking tray, top each with a layer of pesto about 2cms deep (you can store the rest of the pesto in a sterilised jar in the fridge for a couple of weeks and use as normal basil pesto, stirred through pasta etc).
Place the baking tray in the oven and roast for 15 mins.
Serve with buttered new potatoes and wilted spinach.
Recipe by appetite magazine at https://www.appetitemag.co.uk/wild-garlic-pesto-roast-cod/