Watercress mayonnaise
Shop-bought mayo isn't a patch on homemade, especially this vibrant, peppery version - gorgeous with poached salmon
Heat oven to 150C/130C fan/ gas 2. Place a large piece of double-width foil on top of a large baking sheet and brush it with oil, then put the salmon in the centre. Tuck a few generous sprigs of dill and the shallots in the body cavity, then season.
Carefully bring up the sides of the foil to surround the fish, season well inside and out, then pour over the wine.
Seal the foil all the way round, but not too tightly on the fish – you need to give it a bit of space within the parcel. Bake for 1 hr 30 mins.
Once the salmon has cooked, carefully unwrap the foil parcel and pull the dorsal fin on the spine of the fish. If the salmon is ready, it should come away very easily. Reseal the parcel and leave to cool – it will carry on cooking a little more as it cools. If you are not sure that the salmon is cooked sufficiently, return it to the oven for 10 mins more.
When cold, carefully peel away the skin from one side of the salmon. You may need to use a knife to get you started, but it should peel away easily after that. Leave the cooked dill and shallot in place, as you may damage the flesh of the salmon if you try to remove them.
Use a knife to scrape off the brown fatty flesh. It tastes delicious but doesn’t look as attractive as the pink flesh underneath. Carefully turn the salmon over onto a platter and remove the skin and brown flesh from the other side.
To serve, carefully remove the fillets from one side of the fish, leaving behind the bones. You will see that the fish has a natural divide of 2 long fillets on each side. Insert your knife along the centre and carefully ease off each fillet. Transfer the fillets to a platter, bone-side up.
Lift up the central bone from the remaining whole fish – it should come away in one piece – and remove the aromatics. Ease the 2 remaining fillets apart and remove any pin bones. Reassemble the salmon on the platter. Stir the herbs into your mayonnaise and garnish the salmon with watercress, cucumber, herbs and lemon.