Scrub the mussels well under cold running water. Remove the beards and discard any mussels that are open. Place the mussels in a large saucepan with the wine and shallots.

Cover with a tight-fitting lid and cook over a high heat, shaking the pan occasionally, for 5-8 minutes until the mussels have opened. Drain the mussels, reserving the liquid. Discard any that remain closed.

Shell all but a few of the mussels and keep warm. Bring the reserved cooking liquid to the boil, then reduce by half. Strain into jug.

Cook the pasta in a large pan of boiling salted water for 10 minutes or according to the instructions on the packet.

Meanwhile, melt the butter in a frying pan and fry the garlic for 1 minute. Pour in the mussel liquid, cream and saffron strands. Heat gently until the sauce thickens slightly. Remove the pan from the heat and stir in the egg yolk and shelled mussels, and season to taste with salt and pepper.