If you are not as lucky as I am to be married to a fisherman and to have two sons and a son-in-law not too shabby with a fishing rod either, then hake from your fishmonger will have to do. Over the years I have tried many traditional recipes, but I promise you : we have now honed it down to the best.
For the sauce you will need: 6 to 8 onions, 375 ml sugar , 2 tablespoons curry powder , 2 tablespoons turmeric , 2 teaspoons salt , half teaspoon coriander seeds , 4 star anise , 4 cumin seeds(crushed), 2 pieces of cassia , 2 tablespoons of freshly grated ginger , 3 cups of brown grape vinegar , 1 cup of apple vinegar , 1 cup of water , 5 bay leaves.
Put all the ingredients in a pot and boil for 20 minutes. I like to thicken the sauce slightly by stirring in a paste made with 2 flat tablespoons of flour mixed with an extra 125 ml water.
In the meantime coat your fish fillet in flour and seasoning to taste.Then fry in oil and set aside.
Layer the fried fish with onion in sterilized bottles,cover top with cling wrap to prevent vinegar from reacting with lids, screw on and keep for at least 3 days before the bottled fish will be ready. I sometimes just layer it in a flat glass dish, cover the whole lot with cling wrap and leave in the fridge for 3 days before eating.