Bercy Sauce

Ingredients

Equipment Needed

• •1-quart heavy saucepan
• •Small balloon whisk
• •Heatproof measuring jug
• •Flexible silicone spatula

Instructions

1. 1

   Warm the shallots

   Put the shallots in a small heavy saucepan over medium-low heat and stir for 20 to 30 seconds, just until their raw aroma begins to soften. Do not let them color. Immediately moisten with the white wine and fish fumet, or with strained poaching liquor from the same kind of fish when you have it. Bring the liquid to a controlled simmer.

2. 2

   Reduce to one-third

   Simmer uncovered until about 1/3 cup (80 ml) of liquid remains, roughly one-third of what entered the pan. The bubbles will grow slower and slightly heavier, and the shallot fragrance will lose its raw edge. This reduction is the sauce's backbone, so measure it in a heatproof jug if your eye is uncertain. If it goes too far and the pan is nearly dry, add fumet or water one teaspoon at a time until you return to the proper volume. Ça se rattrape.

   Use a small saucepan rather than a wide skillet. A broad pan races through this little quantity and can leave the shallots dry before you notice.
3. 3

   Add the velouté

   Whisk the prepared fish velouté into the reduction and bring the sauce briefly to a boil. Lower the heat and simmer for 4 to 6 minutes, whisking often, until it is nappé (thick enough to coat the back of a spoon) and the shallots are tender. If it turns pasty, loosen it with a teaspoon of warm water; if it runs off the spoon like broth, simmer another minute.

4. 4

   Monter au beurre

   Take the saucepan completely off the heat and wait 20 seconds. Whisk in the cold butter one cube at a time, adding the next only when the last has disappeared. The sauce should grow glossy and supple without becoming oily. Never let it boil after the butter enters. If beads of fat appear, stop adding butter, place 1 teaspoon of cold water in a clean bowl, and whisk in the broken sauce a spoonful at a time until it comes together; then finish with the remaining butter. Ça se rattrape.

5. 5

   Finish and serve

   Whisk in the fish glaze and lemon juice, then fold in the chopped parsley. Taste before considering any salt, since fumet, velouté, and fish glaze may already provide enough. Spoon the Bercy immediately over or around medium-sized poached fish. Keep it beside the stove if it must wait a few minutes, never over direct heat, and whisk once before serving. À table!

Chef Tips

• •Choose a dry, lively white wine without sweetness or heavy oak. Reduction concentrates everything in the glass, including faults, so cook with a wine you are happy to pour beside the fish.
• •Poaching liquor from the fish you are serving is the source entry's first choice. Strain it carefully and skim away excess fat; when there is no poaching liquor, a clean, pale fish fumet is the honest home equivalent.
• •Fish glaze is powerful and may be salty. Four drops should deepen the sauce without announcing themselves; this is seasoning by concentration, not another sauce poured into the pan.
• •Bercy belongs with gently poached sole, turbot, brill, hake, or cod. The fish should be mild enough for the fumet and butter to remain legible, and firm enough not to disappear beneath the sauce.

Advance Preparation

• •The fish fumet and fish velouté are finished components and can be prepared ahead, chilled promptly, and kept cold for up to two days.
• •The sauce may be made through the velouté simmer several hours before dinner. Cool and cover the base, then reheat it gently before mounting with butter and adding the lemon and parsley.
• •Once mounted with butter, Bercy does not enjoy reheating. Finish it as the poached fish is being drained and serve within ten minutes.

Frequently Asked Questions

Nutrition Information

1 serving (about 60g)