First make the poaching liquid for the
fish. Put the peppercorns, 2 tsp salt,
vinegar, fennel, bay leaves and parsley
stalks in a saucepan with 2.5 litres
of water, and bring to the boil. Boil
for 10 mins so all the flavours infuse
into the liquid.
Make sure that you choose a roasting
tin big enough to hold the salmon fillet.
Strain the liquid into the empty tin, bring
to the boil on the hob, then add the
fish, skin-side down, making sure it is
covered in liquid. Scatter around the
lemon slices, and simmer gently for
1-2 mins until the fish changes colour
completely. Cover the surface with a
large piece of foil, turn off the heat and
leave to cool completely. The fish will
cook as the liquid cools.
To make the salsa verde, put all the ingredients into the bowl of a food processor, then blitz to make a bright, slightly chunky sauce. Season to taste.
Carefully remove the salmon to a serving platter and peel away the skin if you like. Serve with the salsa verde, new potatoes and asparagus.