This saffron sauce is another great adaptation of Nathan’s mayonnaise based sauces. Saffron has a unique flavour which works as a wonderful compliment to fish and shellfish.
2 150g-200g sea bass fillets (wild if possible, with the skin on and scaled)
250g live mussels
20 baby spinach leaves
salt for seasoning
rapeseed oil for cooking
For the saffron sauce
3 egg yolks
2 tbsp white wine vinegar
small pinch of saffron
300ml rapeseed oil
100ml fish stock
50ml mussel cooking juices
1 tbsp freshly chopped chives
squeeze of fresh lemon juice
First make the saffron mayonnaise base for the sauce: Soak the saffron in the white wine vinegar for 10 minutes then pour it all in to a food processor along with the egg yolks. Mix the egg yolks and vinegar for 2 minutes then very slowly pour in the rapeseed oil while continuing to mix. Gradually add the oil until you form a thick mayonnaise. Season with salt to taste, then transfer to a sealed container and keep in the refrigerator for up to 3 days.
To prepare the mussels: Make sure the mussels are alive by checking that the shells are closed. Discard any mussel that is open and does not close up as soon you tap it.
Remove the beards from the mussels. These are the small hair-like fibers attached to the mussel at one end. Simply pull them away from the shell. If the mussels are especially dirty or sandy you will need to give them a quick rinse under cold running water to help wash away the dirt without losing the natural flavour.
To cook the mussels: Heat a large pot for 5 minutes, then pour in the mussels and add a splash of water. Place a lid on top and steam the mussels on the highest heat for 3 minutes. Shake the pan and allow a further 2 minutes for the mussels to cook. When the mussels have all opened, remove the pan from the heat and scoop the mussels out on to a tray allowing them to cool. Pass the remaining cooking juices through a fine sieve and retain for later.
When the mussels are cool enough to handle, remove the meat from the shell and discard the shell. keep the mussel meat to one side for later.
To cook the Sea Bass: Pre heat your oven to 180ᵒC. Heat a large non-stick frying pan for 2-3 minutes on a medium to high heat. Add a splash of oil and season the sea bass fillets with salt before placing them in the pan skin side down. Cook on a medium to high heat for 4 minutes then transfer the pan to the oven and cook for 3-5 minutes. When ¾ of the fish is cooked and has turned white (around 2-3 minutes), remove the pan from the oven and turn the fillets over. Leave the pan on the side, off the heat, and allow the fish to continue gently cooking in the pan for a further 2 minutes.
To finish the saffron sauce: Heat the fish stock and the mussel juice in a saucepan until just simmering. Place the mayonnaise base in a separate saucepan and slowly whisk in the hot fish stock and mussel juice until you reach the consistency of single cream. Place the sauce on the heat and gently warm through whilst stirring, being careful not to boil the sauce. When warm, add the mussel meat and spinach leaves then place back on the heat for 30 seconds or just enough to wilt the spinach. Add the chopped chives and the squeeze of fresh lemon juice, adjusting the seasoning where required with salt.
To serve: Pour the sauce in to the middle of two warm bowls, separating the garnish evenly, then place the Sea Bass fillets on top. Serve some steamed new potatoes alongside, and enjoy with a chilled glass of Albarino.