The availability of Thai and Asian ingredients is so much better than it was 10 or so years ago – even down in Dorset at the local car boot sale I've spotted a stand dedicated to Asian ingredients.
Once you find them, banana leaves can be cut to size and frozen for future use.
You can use most types of fish for this but mackerel does work particularly well with its oily flesh.
4 medium-sized mackerel, gutted and scored a few times
For the Thai paste
1tbsp light (not toasted) sesame oil
1 small mild chilli, deseeded and roughly chopped
1 lemongrass stalk, woody outer layer and ends removed and the bulbous end roughly chopped
30-40g galangal or root ginger, peeled and roughly chopped
2 garlic cloves, crushed
4 lime leaves, roughly chopped
½tsp ground cumin
10g coriander leaves
20g Thai basil
1 banana leaf, cut into 4
For the dipping sauce
1tbsp sesame oil
1 small red chilli, deseeded and finely chopped
1tbsp finely chopped galangal or root ginger
1tbsp finely chopped lemongrass
2 lime leaves
1 garlic clove, crushed
3tbsp soy sauce
For the rice
225g basmati rice, rinsed well in cold water
2 lemongrass stalks, bulbous ends crushed
8 lime leaves
Preheat the oven to 200C/gas mark 6. To make the dipping sauce, heat the sesame oil in a pan and fry the chilli, galangal, lemongrass, lime leaves and garlic gently for 1 minute to soften them and release their flavours.
Add the soy sauce, bring to the boil, then allow to cool and pour into a bowl or, ideally, individual dipping-sauce dishes.
Now make the rice. Cook the lemongrass with the lime leaves in about a litre of simmering salted water for 10 minutes.
Add the rice and simmer for 10-12 minutes more until it is just cooked.
Drain in a sieve, then return to the pan, cover with a lid and let it stand for 10 minutes before serving. This will help the rice become nice and fluffy.
In the meantime, while the rice is cooking, prepare the mackerel.
Heat the sesame oil in a pan and gently cook the chopped chilli, lemongrass, galangal, garlic, lime leaves and ground cumin for a couple of minutes until the aromatics are soft.
Tip the pan's contents into a food processor with the coriander and Thai basil, together with a couple of tablespoons of water, and blend to a paste.
Spread this on the fish and wrap each one in a piece of banana leaf, like a parcel, folding the leaf so the edges join beneath the fillet.
Bake for 10-15 minutes, until the tip of a skewer inserted into the centre of a parcel comes out hot.
Place a fish parcel on each plate with a pot of the dipping sauce.
Serve the rice in individual bowls or in a large bowl to be passed around.