This sauce is delicious served over grilled, steamed or baked white fish.
1 shalot - finely chopped
1 medium sized fennel bulb
150 ml fish stock
1 egg yolk
1 tbsp cream
Sweat the shallot in butter until translucent.
Remove any outer stalks from the fennel (save with the feathery leaves) and slice into thin slices.
Add the slices of fennel to the shallots and stir for a few minutes to coat in the butter.
Add 5tbsp of the stock, cover, and simmer gently, until the fennel is cooked.
Place the mixture into a blender and purée adding enough extra stock to make a smooth mixture.
Strain into a saucepan and add the remaining stock.
Adjust the seasoning to taste.
Add the egg yolk mixed with the cream and stir until hot (not boiling).