6 mackerel, gutted and heads removed
1 medium onion, peeled and sliced
100g (3½oz) soft light brown sugar
1 level tbsp coriander seeds, lightly crushed
1 red chili, deseeded and sliced
2-3 bay leaves
568ml bottle malt vinegar
2 Granny Smith apples, cored and diced
3 sticks celery, diced
Crusty or soda bread, to serve
Set the oven to 150°C or Gas Mark 2.
Arrange the fish in a single layer in an ovenproof dish. Place the onion slices on top. Cover with the sugar, coriander seeds, chilli and bay leaves.
Pour the vinegar and 300ml (½ pint) water into the dish, so it covers the fish.
Cover the dish with a lid or a sheet of baking parchment-lined foil. Bake for 50-60 mins, until the fish is very tender.
Meanwhile, mix together the apple and celery with a little seasoning and set aside until ready to serve.
Remove the fish from the oven and serve hot or cold, with the apple and celery mix and bread to soak up the juices.