Make 2 deep slashes into each side of the fish. Sprinkle a few pinches of ground allspice all over the fish, rubbing it into the cuts and the cavity of the fish.
Heat the vegetable oil in a large frying pan, until very hot. Gently lower the fish into the pan and leave to fry on one side for 7-10 minutes, until the snapper is golden brown and crisp. Turn the fish and cook on the other side, gently moving it around to ensure even cooking. Baste with the hot oil. Turn again and baste if necessary. Once cooked, carefuly lift out of the pan and leave to drain on a plate lined with kitchen paper. Leave to rest while you prepare the escovitch.
Pour the vinegar into a large saucepan. Add the onion, chilli, peppers, cho cho, thyme, spring onions, a pinch of ground allspice and black pepper.
Turn the heat to high, place a lid on the pan and steam for 10-15 minutes. Once the vegetables have begun to soften, turn off the heat, add the carrot ribbons and let the heat of the vegetables cook the ribbons for a further 5 minutes.
Put some of the vegetables in the bottom of a large serving dish, place the fish on top and then put more vegetables on top of the fish and pour over some, but not all, of the juice from the pan. Can be eaten hot or cold.