To make the sauce, pound the shallots in a mortar with the garlic, chilli and peanuts until you have a paste.

­In a saucepan, combine the paste with the palm sugar, fish sauce, tamarind and water and bring to the boil, stirring. Simmer for 5 minutes, stirring, until thick and syrupy. Cool.

Wash and dry the leaves and set out on a tray. Break up the smoked trout into bite-sized pieces, discarding bones and skin.

Fold the lime leaves in half along their spines and cut off and discard the spine. Cut the leaves lengthwise into extremely thin strips.

To assemble, top each whole leaf with some smoked trout and a teaspoonful of sauce. (If the sauce has set hard, beat in a spoonful of boiling water.) Scatter with diced lime, peanuts and coriander. Top with a little salmon roe, scatter with shredded lime leaf, wrap and eat.

*The authentic way is to use both lime flesh and skin, very finely diced, so you get tiny bits of each scattered through the leaf filling - this has an astonishing effect in the mouth.