Shellfish Essence

• 1 litre (35 fl oz/4 cups) shellfish stock
• 1

Pour the shellfish stock into a small deep saucepan and bring to a simmer. Reduce the stock for 1 minute. Add the butter, remove from the heat and blend through with a hand-held blender. Leave to cool for 2 minutes. Add the lecithin and blend again to make a stable foam. Season the shellfish essence with salt to taste. Keep warm until required.