Crispy wild salmon with warm lemon and tarragon mayonnaise

From Gary Rhodes The Complete Cookery Year published by BBC Books, price £25 

"The marriage of salmon and asparagus is one that is so outstanding. To finish this combination, I have borrowed a warm, creamy sauce recipe from a very good friend, a Mr Rick Stein. The base to this is a hollandaise sauce, using the oils from a mayonnaise to finish."

Serves 4 as a main course

Ingredients

24-28 medium asparagus spears
4 x 175g (6oz) portions of wild salmon fillet,
pin-boned (page 9) with skin on (scaled)
salt and pepper
flour, for dusting
2 tablespoons cooking oil
knob of butter, plus more for brushing
coarse sea salt (optional)

For the mayonnaise

125ml (4fl oz) sunflower or groundnut oil
3 tablespoons extra virgin olive oil
2 egg yolks
juice of 1z2 lemon
Cayenne pepper
1 heaped teaspoon chopped tarragon

To make

1. First make the mayonnaise, which can then be kept warm while completing the dish. Put the sunflower or groundnut oil and the olive oil in a small saucepan and place on a very low heat just to warm through.
2. Mix the egg yolks and lemon juice with 2 tablespoons of water in a bowl, and place over a pan of simmering water, making sure the water is not touching the base of the bowl. Whisk the yolk mixture vigorously until thick and frothy, then continue to whisk until the frothy consistency becomes almost creamy.
3. Remove the bowl from the heat and gradually whisk in the warmed oils. Once all the oil has been added, whisk in 2-3 tablespoons of warm water to loosen the thick sauce. This addition of extra water will prevent the oils and eggs from separating. If the sauce continues to thicken as it sets, simply add a little more water. Season with salt and Cayenne pepper, adding the tarragon and setting aside to keep warm while cooking the salmon and asparagus.
4. Trim the spiky ears from along the asparagus stalks and break or cut the grey-white stalk base away, keeping the spears a uniform length.
5. Season the salmon fillets with salt and pepper and lightly flour the skin sides only. Put a large pan of salted water on to boil.
6. Heat the cooking oil in a large frying pan and place the fillets in, skin-side down. Fry on a medium-hot heat for 6-7 minutes, not shaking or moving the fish, just allowing the skins to fry and crisp.
7. Turn the fillets, add the knob of butter and remove the pan from the heat. The remaining residual heat will continue to cook the fish for a further few minutes, keeping the flesh moist and buttery.
8. After turning the salmon, plunge the asparagus tips into the large saucepan of rapidly boiling salted water. Cook for just 2-3 minutes, until tender; 4 minutes should be the maximum. Lift the spears from the pan, drain well and brush with butter to add more flavour and create a shine.
9. Place the spears side by side on plates and season with a sprinkle of coarse sea salt, if using. Sit the crispy salmon on top, offering the warm lemon and tarragon mayonnaise separately.