- 2 kg / 4½ fresh mussels, scrubbed and bearded
- 250 g / 9 oz shallots, finely chopped
- 300 ml / ½ pint / 1¼ cups medium white wine, such as Vouvray
- generous pinch of saffron threads (about 12 strands)
- 75 g / 3 oz / 6 tbsp butter
- 2 celery sticks, finely chopped
- 5 ml / 1 tsp fennel seeds, lightly crushed
- 2 large garlic cloves, finely chopped
- 250 ml / 8 fl oz / 1 cup fish or stock
- 1 bay leaf
- pinch of cayenne pepper
- 2 large (US extra large) egg yolks
- 150 ml / ¼ pint / ⅔ cup double (heavy) cream
- juice of ½-1 lemon
- 30-45 ml / 2-3 tbsp chopped fresh parsley
- salt and ground black pepper
- Discard any mussels that do not shut when tapped sharply.
- Place 30 ml / 2 tbsp of the shallots with the wine in a wide pan and bring to the boil. Add half the mussels and cover, then boil rapidly for 1 minute, shaking the pan once. Remove all the mussels, discarding any that remain closed. Repeat with the remaining mussels. Remove the top half-shell from each mussel. Strain the cooking liquid through a fine sieve into a bowl and stir in the saffron, then set aside.
- Melt 50 g / 2 oz / 4 tbsp of the butter in a heavy pan. Add the remaining shallots and celery and cook over a low heat, stirring occasionally, for 5-6 minutes, until softened but not browned. Add the fennel seeds and half of the garlic, then cook for another 2-3 minutes.
- Pour in the reserved mussel liquid, bring to the boil, and then simmer for 5 minutes before adding the stock, bay leaf, and cayenne. Season with salt and pepper to taste, then simmer, uncovered, for 5-10 minutes.
- Beat the egg yolks with the cream, then whisk in a ladleful of the hot liquid followed by the juice of ½ lemon. Whisk this mixture back into the sauce. Cook over a very low heat, without allowing it to boil, for 5-10 minutes until slightly thickened. Taste for seasoning and add more lemon juice if necessary.
- Stir the remaining garlic, butter, and most of the parsley into the sauce with the mussels and reheat for 30-60 seconds. Distribute the mussels among six soup plates and ladle the sauce over. Sprinkle with the remaining parsley and serve.