For the mackerel, preheat the grill to high. 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 ...

Place onto a wax paper lined tray and chill for an hour in the fridge. Do not skip this step! It's important, otherwise your ...

Lightly drizzle olive oil over a baking tray and place the mackerel fillets on top, skin-side down. Season with salt, pepper, some of the rosemary and all of the thyme, plus half the lemon zest.