Genoa Sauce

Ingredients

Equipment Needed

• •Medium stone or ceramic mortar and pestle
• •20 cm (8-inch) nonreactive mixing bowl
• •Balloon whisk
• •Fine-mesh sieve
• •Small saucepan
• •Slotted spoon
• •Clean kitchen cloth
• •Digital kitchen scale

Instructions

1. 1

   Prepare the cold station

   Wash and dry all four herbs, keeping their quantities equal. Bring a small saucepan of water to a full boil and set a bowl of iced water beside it. Have the mortar, fine sieve, and a clean cloth ready before the herbs enter the water, because their color depends on cooling them immediately.

2. 2

   Scald the four herbs

   Drop the chervil, parsley, tarragon, and salad burnet into the boiling water together and scald them for exactly one minute. Lift them straight into the iced water, stir until completely cold, then drain and squeeze with real conviction in the clean cloth. Water left in the herbs weakens the emulsion, so squeeze again if they still feel spongy. Pound or chop them to a pulp, press that pulp through the fine sieve, and measure 1 tablespoon (15 ml / about 8 g) of smooth herb purée. Keep it cold.

3. 3

   Pound the nuts smooth

   Put the pistachios and pine nuts in the dry mortar and pound until they become a smooth, cohesive paste with no grit beneath the pestle. Scrape the mortar often so every fragment passes under it. Only when the paste is fine should you work in the cold Béchamel. A small processor merely chops this quantity and leaves grains behind; the mortar is not ceremony here, it is the technique.

4. 4

   Build the mayonnaise

   Transfer the nut paste to a medium bowl and whisk in the two yolks, salt, and white pepper until perfectly even. Anchor the bowl on a damp cloth. Add the oil drop by drop at first, whisking without pause; once about ¼ cup (60 ml) has entered and the sauce holds a thick gloss, add the remaining oil in a thread. Work in the lemon juice a teaspoon at a time whenever the sauce becomes very stiff, finishing with all the oil and lemon. If the emulsion separates, stop pouring. Ça se rattrape: whisk 1 teaspoon of warm water in a clean bowl and feed the broken sauce into it a teaspoon at a time. If it still refuses, begin with the optional fresh yolk and whisk in the broken sauce slowly, then continue.

5. 5

   Green the sauce

   Whisk the measured herb purée into the mayonnaise until the color is even and no dark streaks remain. The sauce should fall from a spoon in a slow, glossy ribbon. If it is too tight, loosen it with a few drops of cold water; add no more herb purée, because the source ratio gives the sauce its balance rather than turning it into an herb paste.

6. 6

   Chill and serve

   Press reusable food wrap directly against the surface and chill the Sauce Génoise for at least 30 minutes. Stir gently, then taste it cold and correct the salt or lemon if needed, since cold softens both. Serve 2 to 3 tablespoons beside each portion of cold poached salmon, trout, turbot, or another firm fish. Keep the sauce chilled until the table is ready. À table!

Chef Tips

• •Use raw, unsalted nuts. Roasted pistachios or pine nuts dominate the herbs and can make the finished sauce taste heavy rather than fresh.
• •If pine nuts are unavailable, the source permits the same weight of blanched sweet almonds, 1 rounded tablespoon (15 ml / 9.5 g). Keep the pistachios. The almond version is milder, but it remains within the formula.
• •Salad burnet has a cool, cucumber-like flavor and may be sold simply as burnet. Do not use scarlet pimpernel. If salad burnet cannot be found, replace it with the same weight of extra chervil and understand that its distinctive cool note will be missing.
• •Keep the yolks and oil at roughly the same cool room temperature. A very cold yolk meeting warmer oil makes the emulsion slower to establish, though it can still be rescued.
• •Because this sauce contains raw yolks, pasteurized eggs are the sensible choice. Refrigerate it promptly, keep it below 40°F (4°C), and use it within two days. Do not freeze it.
• •Serve with a dry, mineral white such as Muscadet. The wine should clear the richness of the mayonnaise and leave the herbs intact, not compete with them.

Advance Preparation

• •The herb purée can be prepared up to four hours ahead. Press reusable food wrap against its surface and refrigerate it promptly to protect its color.
• •The completed Sauce Génoise can be made one day ahead and held covered in the refrigerator. Stir gently before serving and loosen it with a few drops of cold water if it has tightened.
• •Cold poached fish can be cooked and chilled one day ahead, then brought out shortly before serving. Keep both fish and sauce cold until the table is set.

Frequently Asked Questions

Nutrition Information

1 serving (about 40g)