It's very important to use small oysters — such as Kumamoto or Prince Edward Island — in this soup. The oysters themselves (not the shell) should be no more than 1 to 1 1/2 inches in diameter. When we tested the recipe with larger ones, the flavor was much too briny.
·Fried leeks can be made 3 days ahead and kept in a sealed plastic bag at room temperature.
·Soup base (without oyster liquor, half-and-half, oysters, and cayenne) can be made 2 days ahead and cooled, uncovered, then chilled, covered.
Recipe information
Yield
Makes 8 servings (about 11 cups)
Ingredients
For fried leeks
For soup
Special Equipment
Preparation
Fry leeks:
Step 1
Cut leeks crosswise into 2-inch lengths, then cut lengthwise into enough very thin strips to measure 2 cups. Wash leek strips in a bowl of cold water, agitating them, then lift out and pat dry.
Step 2
Heat oil in a deep 4-quart heavy saucepan until it registers 360°F on thermometer. Fry leeks in 8 batches, stirring, until golden, about 10 seconds per batch. Transfer as fried with a slotted spoon to paper towels to drain. Cool completely (leeks will crisp as they cool).
Make soup:
Step 3
Pick over oysters, discarding any bits of shell, and rinse well. Wash chopped leeks in a bowl of cold water, agitating them, then lift out and drain well. Peel potatoes and cut into 1/2-inch cubes. Cook leeks, potatoes, and salt in butter in a 4-quart heavy saucepan, covered, over low heat, stirring occasionally, until leeks are golden and potatoes are beginning to soften, about 15 minutes. Add water and simmer, covered, over moderate heat until potatoes are very tender, about 10 minutes. Purée soup in batches in a blender until very smooth (use caution when blending hot liquids), transferring to a bowl.
Step 4
Return soup to saucepan. Add oyster liquor and half-and-half and bring to a simmer over moderate heat, stirring occasionally (do not boil). Add oysters and cayenne and cook, stirring occasionally, just until oysters become plump and edges curl, about 3 minutes. Season with salt.
Step 5
Serve soup topped with fried leeks.
