300 g (10 oz) monkfish fillet, boned and cut into 1.5 cm (3/4 inch) thick slices
400 g (13 oz) spaghetti
salt and pepper
chopped tarragon leaves, to garnish
Pour the measurement water over the saffron in a heatproof bowl and leave to infuse.
Heat the butter in a large saucepan, add the fennel and cook over a medium heat for 5 minutes until softened. Pour over the wine and saffron with the soaking liquid and add the mussels. Cover with a lid and cook for 5 minutes until the mussels have opened. Discard any that remain closed. Stir through the crème fraîche and season.
Meanwhile, heat the oil in a nonstick frying pan, add the monkfish and cook over a high heat for 3 minutes on each side or until just cooked through. Carefully stir the monkfish into the mussel sauce.
While the mussel sauce is cooking, cook the pasta in a large saucepan of salted boiling water according to the pack instructions until al dente. Drain, reserving a little of the cooking water. Stir through the mussel sauce, adding a little cooking water if needed, and season.
Spoon into serving bowls and serve sprinkled with the tarragon.