Start by making the broth. Add the vegetable oil to a hot wok, then sauté the onion, garlic, shallots and ginger until browned.
Stir in the tamarind pulp and chilli flakes. Add the reserved fish bones and toss to coat them well.
Add the peanuts, sugar, fish sauce, soy sauce, coconut juice, lemongrass, lime juice, half the beaten egg and a pinch of sea salt. Add the fish bones and simmer for 15 minutes.
On a separate plate, mix the sliced fish fillets with the pepper and the remaining egg.
Take one lettuce leaf and place a little cabbage, mint, spring onion, coriander, water spinach and a few fish slices on top. Wrap the lettuce up around the filling, and then secure the ends with a bamboo skewer. Repeat with the remaining ingredients, securing each parcel with a bamboo skewer.
Cook the fish parcels in the simmering broth for 1 minute, then enjoy straight away.