Preheat the oven to 200C/400F/Gas 6.
To make the salmon, in a non-stick frying pan heat the olive oil and butter.
Season the salmon and place in the hot pan, skin side down. Leave for 3-4 minutes before carefully turning over. Cook for another two minutes.
Place in the oven and cook for 5-6 minutes or until cooked to your liking.
To make the sauce, scrub the mussels well, discarding any that are cracked or will not close when tapped.
Melt the butter in a large saucepan and add the shallots, leeks, fennel and mushrooms. Then add the curry powder, saffron and a splash of pastis. Bring to the boil.
Add the mussels, the cream and the bay leaf and finally the parsley and the butter. Season to taste.
Once the mussels open the sauce is ready to serve.
Serve at once with the pan-fried salmon fillet, sprinkled with the saffron strands.