Salmon with Tarragon Hollandaise

Make the tarragon hollandaise: Heat the white wine vinegar and 1 tablespoon of water with the stalks from the tarragon and the peppercorns in a small pan, and reduce to 1 tablespoon. Remove the stalks and the peppercorns from the pan and discard.

Whisk the egg yolks in a bowl with an electric whisk. Slowly, while whisking, pour in the hot vinegar. When it has all been incorporated, use the now-empty pan to melt the butter. When it starts frothing, pour it very slowly into the egg mixture, whisking all the time. Mix in lemon juice to taste, and the chopped tarragon leaves, and season with salt an pepper.

Cook the asparagus and samphire: Bring a large pan of water to the boil over a high heat. Add the asparagus, boil for 1 minute, and then add the samphire. Boil for 1 minute more. Drain and drizzle with some of the remaining lemon juice, and season with salt and pepper.

Cook the salmon: Pat the salmon fillets dry with kitchen paper. Heat the oil in a large frying pan over a high heat. Put the fillets in a pan, skin side down, and immediately turn the heat down low. Use a fish spatula to press down on the fillets for the first minute so the skin doesn't curl up. Cook for 3-4 minutes, then flip over and cook on the other side for about 1 minute, until the salmon is just cooked.

Serve the salmon with the warm asparagus and samphire and the tarragon hollandaise.