You’ll know that your whole fish is thoroughly cooked when the dorsal fin (the one on the back) pulls away easily.
Heat the grill to High, or fire up the barbecue. Slash the fish a few times on each side, then season with black pepper. Grill or barbecue the fish for 3-5 mins on each side, until charred and cooked through (see Tip).
Heat the oil in a frying pan (you can put the pan on the barbecue rack), then fry the ginger, garlic and chillies for about 2 mins until the garlic is lightly golden. Take off the heat and toss in the spring onions and cherry tomatoes. Lift the fish onto a plate, splash with the vinegar, then spoon over the contents of the
pan and splash with soy sauce.