To make the salad, combine the lime juice and sweet chilli sauce in a large bowl and add the
fish sauce and palm sugar, to taste. Add the cucumber and onion. Quarter and core the pear, slice
it thinly and add it to the bowl. Chop half the mint and basil leaves, add to the bowl and toss to
coat. Cover and set aside in a cool place for 2 hours.
Meanwhile, combine the lemon grass, fish sauce and palm sugar in a large bowl. Slice the cod
into 1cm / 1/2 in thick slices and add to the bowl. Toss to coat, cover with plastic wrap and chill
for 1 hour.
Line a large bamboo steamer with baking paper and cover with as many slices of cod as will fit
in a single layer. Place over a wok or saucepan of boiling water and steam for 4 minutes, or until
cooked through. Repeat with the remaining fish.
To serve, toss the remaining mint leaves and the peanuts through the salad. Divide among 4
serving plates and top with the fish and the remaining basil leaves.