Start by filleting the fish and sprinkling lightly with salt and pepper and fish spice, (fish rub, optional)
Preheat the oven to 180 to 190 C (350–375 F)
Lightly dust the fish with flour, shake off excess, then fry in a little oil until just golden. Transfer to an ovenproof glass dish.
In a large saucepan, heat a little olive oil and sauté the onions until soft and translucent. Add the garlic, ginger and chilli (if using) and cook until fragrant.
Stir in the curry powder, masala, turmeric, ground cumin, coriander seeds, peppercorns and bay leaves. Cook for 1–2 minutes to release the spices.
Pour in the vinegar and water, add the sugar and salt, and bring to a gentle simmer. Simmer for 8–10 minutes.
Mix the corn flour with 30 ml water to form a smooth paste, stir into the sauce and bring to a gentle boil until slightly thickened. Taste and adjust seasoning if needed.
Pour the hot sauce over the fish. Bake for 30 minutes.
Allow to cool, then refrigerate. For best flavour, serve after 1–2 days with fresh bread and butter.
Note: Pickled fish is best served a day or two after its made.
Serve with fresh bread and butter.