Halibut Parcels in Lettuce

Wilt the lettuce leaves in boiling water, and refresh them in cold water.
This will make them more manageable.
Shell and devein the prawns and mince or chop them finely.
Chop the spring onions finely, and mix with the prawns.
Spread the mixture on to the lettuce leaves and place a bit of halibut on the top of each.
Dust them with paprika, then put in more prawn and roll up into neat parcels.
If necessary, use two leaves per parcel to make them water-tight.
Peel and trim if necessary, and then put the baby carrots, fennels, leeks and shallots into the bottom of a large pot and add chicken stock and wine inches Bring to boil and simmer for 20 minutes.
Carefully place the fish parcels on top of the vegetables and cook with the lid on for another 8-10 minutes - but no more - depending on the thickness of your parcels.
Gently tip all the liquid from the pot into another pan to finish the sauce, holding back the vegetables and fish with the lid.
Shake the cornflour in a little bit of cold water and whisk into the liquid.
Simmer until thickened, then turn off the heat.
Whisk the egg whites in a bowl until thye peak, fold in the yolks.
Pour the warm stock into the egg mixture, stirring with a whisk.
Put bowl over a saucepan of boiling water and gradually whisk in the lemon juice.
Continue to whisk until the sauce thickens like a custard.
Adjust seasoning with salt and pepper.
Return the sauce to the pot of fish and parcels and vegetables, leave for 5 minutes for the flavours to mingle.