Instructions: Cut off and discard tops of the leeks at the point where they turn from light to dark green. Split the remaining portion lengthwise in half, keeping the roots attached so that the layers will not fall apart. Wash thoroughly, getting between the layers. Thinly slice them into half circles; discard roots.

Melt butter in a 4-quart saucepan over medium heat. Add leeks and garlic; cook, stirring often, until softened and just beginning to turn golden, about 10 minutes. Add stock and salt; bring to a simmer. Turn heat to low, cover and cook at a bubbling simmer for 15 minutes to soften leeks. (The soup may be made to this point up to two days ahead and refrigerated. Return to heat before continuing.)

Slice head of lettuce crosswise into 1-inch-wide strips; discard the base. Wash lettuce in a deep basin of cold water; drain in a colander. Stir lettuce into hot soup, increase heat to medium. Cook, uncovered, until lettuce is wilted and softened, about 5 minutes. Stir in tarragon.

Put half of soup in the container of an electric blender. Hold the lid down with a dry towel. Turn the blender on low speed so that the soup doesnt splash out, then gradually increase speed and blend until very smooth. Repeat with remaining soup.

Return pureed soup to pot; gently reheat. Taste; season with pepper and additional salt if needed. Serve in warmed bowls.

To garnish, stir together creme fraiche or sour cream with heavy cream; drizzle over soup.

This recipe yields 6 servings.

Comments: Although this recipe calls for romaine, other lettuces (except iceberg) can be substituted. We made it with bibb lettuce, and it worked beautifully.

Use the best stock you can find. If youre using canned and you have time, simmer the canned stock with some chicken wings and backs to enrich the flavor.

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