Preheat the oven to 190°C.
Mix the salt and ground turmeric and rub the mixture into the fish.
Blend coconut, coriander, chillies, garlic, ginger, cumin, sugar, lime juice, and mint into a paste, adding water if needed.
Rub the herb paste inside the belly and over the skin of each mullet.
Soften the banana leaves briefly over a gas flame or with a blow torch.
Place a fish in the center of each leaf, fold into parcels, and tie with string.
Place parcels in a tray, sprinkle with malt vinegar and water, and bake for 15-20 minutes.
Halve the hard-boiled eggs, crumble the yolks, and finely chop the whites.
Combine the egg components with the remaining salad ingredients and season with salt and pepper.
Open the banana parcels on plates and serve the salad alongside the fish.