Lady Curzon Soup

Ingredients

• 0.5 teaspoon curry powder 
• 1 large egg yolk 
• 1  garlic clove smashed
• 0.5 cup cup heavy whipping cream 
• 1 tablespoon madeira wine 
• 2 lb mussels scrubbed (preferably cultivated)
• 1 large onion chopped
• 2  turkish bay leaf 
• 1.5 tablespoons butter unsalted
• 1.5 cups water 

Equipment

• bowl
• sauce pan
• whisk
• pot
• sieve
• kitchen thermometer
• slotted spoon

Directions

1. Cook all broth ingredients, covered, in a 4- to 5-quart heavy pot over moderately high heat until mussels just open wide, 4 to 6 minutes.
2. Transfer mussels with a slotted spoon to a bowl and reserve for another use. (Discard any unopened mussels.)
3. Pour broth through a coffee-filter-lined sieve into a bowl, discarding solids. Strain broth again through same lined sieve into a 2-cup glass measure and reserve 1 cup for soup. (Freeze remainder if desired.)
4. Heat butter in a 1-quart heavy saucepan over moderately low heat until foam subsides.
5. Add curry powder and cook, stirring constantly, until just a shade darker, about 1 minute.
6. Add Madeira and bring to a boil.
7. Add mussel broth and bring to a boil.
8. Whisk together cream and yolk in a bowl, then add broth mixture in a slow stream, whisking constantly. Return soup to saucepan and cook over moderately low heat, stirring, until just slightly thickened and registers 170°F on thermometer, about 2 minutes. (Do not simmer.) Divide among glasses.
9. Soup can be made 1 day ahead and cooled, uncovered, then chilled, covered. Carefully reheat (do not let simmer) before serving.