Steamed lime haddock with mango and pepper salsa

This chilly wet summer has sent me scurrying back to favourite dishes I'd never normally cook between May and September. On the rare nice days we've had, though, I've been buying the best seasonal veg at my local market and seeing what's on the slab at the fishmongers. In warm weather I don't want heavy food that lies like a stone in my stomach fish is my first choice for something light and healthy as well as versatile. Whatever fish I buy, I usually steam it or bake it en papillote, as it traps all the flavours and juices and you don't need to add oil.

What you need: 
For the fish
Haddock fillet
1 lime
2 spring onions
1 small stalk of fresh lemongrass
a few slivers of sliced fresh ginger

For the salsa
1/2 a ripe mango
1/2 a red pepper, deseeded
2 spring onions
A few sprigs of fresh coriander

What to do:
Put the fish on a large sheet of tin foil and pull the edges up slightly to start making a pocket. Zest the lime and scatter it over the fish. Shred the spring onions lengthways, slice the lemongrass finely and scatter these and the ginger slices over the fish. Squeeze the juice from the lime and drizzle half of it over the fish. Close the foil parcel tightly.

Bring a pan of water to the boil and then pop a steamer over the top and steam the fish for 10-12 minutes, depending on the size and thickness of the fish.

Make the salsa. Cut the mango into cubes, dice the red pepper and slice the spring onions on the diagonal. Chop the coriander finely and add, then pour over the rest of the lime juice. Season to taste then mix well.

Plate up, keeping the spring onions and ginger with the fish (if, like me, you plan to eat them) and pile the salsa alongside.

Cook's tips: 
En papillote means "in paper", but tin foil works just as well as baking parchment. 

You don't need a special steamer pan to steam food. One of those Chinese bamboo lidded steamer baskets works just as well in a pan as in a wok. Or you can improvise, as I do - I use a metal sieve over the top of the pan, which also makes lifting the food out very easy.

Preparing a mango can be a bit fiddly but I've always found the easiest way is to quarter it with a sharp knife then insert the knife blade inside to cut round the stone and ease each quarter off it. Once the stone's out, cut the flesh lengthways and across then carefully cut the cubes off the skin.