Crème de Cerfeuil Bulbeux, otherwise Chevreuse

Ingredients

Equipment Needed

• •Heavy 3 to 4-quart saucepan with lid
• •Small saucepan for warming the white consommé
• •Countertop blender or powerful immersion blender
• •Fine-mesh sieve, about 8 inches (20 cm)
• •Flexible spatula and soup ladle

Instructions

1. 1

   Prepare roots and garnish

   Peel the tuberous chervil thinly, trim away any woody ends, and mince the roots into even pieces about 1/4 inch (6 mm) across. Uniform pieces soften together, which matters when the soup must pass perfectly smooth. Cut the cooked chicken and truffle en julienne, into very fine matchstick rods, measure one tablespoon of each, cover them, and hold them for serving.

   Tuberous-root chervil oxidizes only mildly, but don't leave the peeled roots waiting about. Mince them just before the butter is ready.
2. 2

   Étuver in butter

   Melt the butter over low heat in a heavy 3 to 4-quart saucepan. Add the minced roots and turn them until every piece gleams with butter, then cover and étuver, meaning stew gently in their own moisture and butter, for 12 to 15 minutes. Stir every few minutes. The roots should soften around the edges but remain entirely pale. If the butter begins to brown, lift the roots into a clean saucepan immediately and leave the browned solids behind; add a small spoonful of pale butter if the pan looks dry. A little color can be contained, but don't scrape it into the soup.

3. 3

   Cook in Béchamel

   Fold the warm Béchamel into the buttered roots and bring the mixture only to the faintest tremble. Cook uncovered over very low heat for 25 to 35 minutes, stirring across the bottom and into the corners often, until a root piece crushes to a smooth paste between two fingers. The flour and milk in Béchamel make scorching the chief danger. If the bottom catches, stop stirring, pour the unburned soup into a clean saucepan, and leave the stuck layer untouched. The clean upper portion is entirely recoverable.

4. 4

   Blend and sieve

   Blend the root and Béchamel mixture until completely smooth. With a countertop blender, work in batches, fill the jar no more than halfway, vent the lid, and begin at low speed before increasing it. Press the purée through a fine-mesh sieve with a flexible spatula, leaving only dry fibers behind. This replaces the classical tammy without abandoning its purpose. If the purée remains gritty, the roots were not tender enough; return it to low heat with 1/2 cup of the measured white consommé for 10 minutes, then blend and sieve again.

5. 5

   Adjust with consommé

   Return the sieved purée to the clean saucepan and whisk in 2 1/2 cups of the warm white consommé gradually. Heat gently for 5 minutes, then judge the body: Chevreuse should coat a spoon with a thin satin film and pour in an unbroken ribbon, never sit like mashed roots. If it is too thick, add the remaining consommé a few tablespoons at a time. If it is thin, let it reduce at a bare simmer before the cream goes in. Ça se rattrape. Taste and add salt only if the Béchamel and consommé have not already supplied enough.

6. 6

   Cream and serve

   Warm the soupière or individual soup bowls. Take the saucepan completely off the heat and whisk in all but 2 tablespoons of the cold cream, then add the reserved cream once the surface is smooth. If oily beads appear because the pan was too hot, wait one minute and whisk the reserved cold cream in vigorously until the soup returns to a satin finish. Never boil it after the cream is added. Place the chicken and truffle juliennes in the warmed vessel, pour the Chevreuse over them, and serve at once. À table!

Chef Tips

• •Cerfeuil tubéreux is the market name to ask for. It is a small brown root with pale flesh, not leafy chervil and not chervil root gathered from an herb plant. If you cannot find it, postpone Chevreuse; parsnip makes a perfectly good cream soup, but it makes a different one.
• •Have the prepared Béchamel and white consommé ready before beginning. The source treats each as a finished foundation, so don't rebuild either one inside this soup. Warm them separately and gently before they meet the roots.
• •Use a white consommé with no roasted color. A brown stock will overwhelm the root and turn the ivory soup beige, changing both its flavor and its character.
• •Fresh black truffle is magnificent here, but a good preserved whole truffle is the honest classical pantry answer outside its season. Drain it well and cut it finely; truffle paste and flavored oil do not supply the same texture or aroma.
• •The source also permits preparing the soup as a velouté. That is a separate canonical route using a finished velouté foundation in place of Béchamel, not a halfway substitution once this version is underway.
• •Serve Chevreuse as the first course with a dry Champagne or a restrained white Burgundy. Keep the portion modest enough that the truffle and root remain a promise of the meal to come.

Advance Preparation

• •The prepared Béchamel and white consommé may be made up to 2 days ahead, chilled promptly, and warmed separately over low heat before use.
• •The root and Béchamel base can be cooked, blended, and sieved 1 day ahead. Cool it quickly in a shallow covered container, refrigerate, then reheat gently and add the white consommé and cream shortly before serving.
• •Cut the chicken and truffle juliennes up to 4 hours ahead and keep them covered in the refrigerator. Let them lose their deep chill while the finished soup reheats so they do not cool the first ladleful.

Frequently Asked Questions

Nutrition Information

1 serving (about 245g)