Betel leaves with crab, kaffir lime and chilli

150g spanner crab meat

1 long red chilli, seeded and sliced

2 kaffir lime leaves, sliced finely

1 large bunch coriander leaves, chopped roughly

1 shallot, peeled and diced

4 mint leaves, sliced finely

4cm (2in) piece lemongrass,

white part only, sliced

1 tablespoon crispy fried shallots

2 tablespoons galangal paste

1 lime, juiced

pinch chilli powder

10 betel leaves

1 tablespoon salmon or trout roe