Put your fish fillets skin side down in a cold non-stick frying pan. Turn the heat on to high. Season the fish fillets with a tiny pinch of sea salt and a pinch of black pepper from a height. Let the fish cook for most of the time on the skin side – give it 4 or 5 minutes without touching it, until the skin is really golden and crispy, then use a fish slice to flip it over to cook for just 30 seconds on the other side. Add a good squeeze of lemon juice to the pan, avoiding the crispy skin, then turn the heat off and give the pan a shake. Delicious served with mashed potato and steamed seasonal veg.