Season the fish with salt and pepper, then slash the skin 3 times. Heat a heavy-based frying pan and add 1 tbsp oil. Once hot, fry the fish, skin-side down, for 5 mins or until the skin is very crisp and golden. The fish will be almost cooked through. Turn over, cook for another 30 secs-1 min, then transfer to a serving plate and keep warm. You’ll need to fry the fish in 2 batches.
Heat the remaining oil, then fry the ginger, garlic and chillies for about 2 mins until golden. Take off the heat and toss in the spring onions. Splash the fish with a little soy sauce and spoon over the contents of the pan.