Put the mackerel fillets on the grill tray, brush with the wholegrain mustard and season with salt and pepper. Grill them for 2-3 minutes, then turn over and grill for a further minute ...

Preheat the grill to high. Mix all of the remaining spiced mackerel ingredients together in a bowl to form a thick, spiced butter and season well with sea salt and freshly ground black pepper.

Cut the heads off very fresh mackerel. Gut and clean them but keep whole. Bring the water to the boil, add the salt and the mackerel. Bring back to boiling point, and remove from the heat.