Purée d’Oignons, dite Soubise

Ingredients

Equipment Needed

• •8-quart stockpot for scalding
• •6-quart wide heavy sauté pan or Dutch oven
• •Food processor with pulse control or a sharp chef’s knife
• •Sturdy fine-mesh sieve or chinois
• •Flexible silicone scraper
• •Balloon whisk

Instructions

1. 1

   Mince, scald, dry

   Bring a large pot of water to a full boil. Mince the onions finely and evenly, working in batches if you use a food processor and pulsing only until the pieces are small, not wet paste. Scald the onions in the boiling water for exactly 3 minutes, then drain them thoroughly. Spread them over clean towels and press firmly until their surfaces feel dry. This scalding tempers the raw sulfurous edge, but the drying is just as important: wet onions simmer in water instead of stewing honestly in butter.

   A food processor replaces many chopping hands, not judgment. Pulse in small batches and stop while the pieces remain distinct; onion pulp sheds too much liquid and is miserable to dry.
2. 2

   Stew without color

   Melt the stewing butter in a wide, heavy pan over low heat without letting it brown. Add the dried onions and turn them through the butter until every piece glistens. Cover loosely and stew for 25 to 35 minutes, stirring from the bottom every few minutes, until the onions are completely tender, ivory-colored, and deeply fragrant. This stewing increases their flavor, and it must stay pale. If golden spots begin forming, pull the pan from the heat, add 2 tablespoons (30 ml / 30 g) water, and scrape the pale fond into the onions before lowering the heat. Ça se rattrape. A few blond flecks can be stopped; a pan of mahogany onions has become another sauce.

   Use your widest heavy pan. A deep, narrow pot traps moisture and encourages uneven cooking, while a thin pan scorches before the onions soften.
3. 3

   Bind and simmer

   Stir in the warmed thickened Béchamel specified for Soubise Sauce (No. 104), followed by the powdered sugar and 1½ teaspoons (7.5 ml / 9 g) of the salt. Bring the mixture only to a lazy bubble, then cook uncovered over the gentlest heat for 30 minutes, stirring frequently across the pan floor. It should thicken into a soft, cohesive purée without catching. At the first scorched speck, stop stirring and transfer the unburned upper portion to a clean pan without scraping the bottom; loosen it with a tablespoon of the measured cream and continue gently. Burnt flavor cannot be whisked away, but an early catch can be left behind.

4. 4

   Pass through sieve

   While the mixture is still warm, press it through a sturdy fine-mesh sieve or chinois with a flexible scraper, working in manageable portions. This is the home equivalent of the tammy, and it removes the last onion fibers while preserving the sauce’s dense, satin texture. Scrape the underside of the sieve often, because much of the finest purée gathers there. Do not abandon the solids after one pass; keep pressing until only a dry spoonful of fibrous residue remains.

5. 5

   Finish the Soubise

   Return the sieved purée to a clean pan over low heat and stir in the cream. Taste, then add the remaining salt only as needed. Remove the pan from the heat and monter au beurre, mount with butter, by whisking in the cold diced butter a few pieces at a time until each addition disappears. The finished Soubise should gleam, mound softly on a spoon, and settle without running like soup. Never boil it after the final butter. If butter pools on the surface, take the pan off the heat and whisk in 1 tablespoon (15 ml / 15 g) cold cream; if needed, begin with another spoonful of cold cream in a clean bowl and whisk the sauce into it gradually. Ça se rattrape.

6. 6

   Hold and serve

   Serve the Soubise warm beside roast lamb, veal, poached eggs, or plainly cooked vegetables. For a short hold, press a buttered round of parchment directly against the surface and set the covered pan over barely warm water for no longer than 30 minutes. Stir gently before serving and loosen with a spoonful of cream if it has tightened. Bring the sauce generously, not in decorative dots. À table!

Chef Tips

• •Use ordinary yellow onions. Sweet onions can push the sauce toward sugary softness, while red onions spoil its ivory color. The everyday onion has the backbone this long butter stewing needs.
• •Reach for thickened Béchamel as a finished component. It should mound on a spoon rather than flow freely, because the onions bring their own moisture and a thin Béchamel leaves the finished Soubise loose.
• •The powdered sugar does not make this a sweet sauce. Its small measure rounds the onions after scalding and supports the flavor the butter stew has already built.
• •The sieve is worth the labor. A blender can make the mixture airy while leaving fine fibers behind; passing it produces the close, satin body intended by the formula.
• •Soubise is especially good with roast lamb, where its pale sweetness answers the meat without covering it. It also turns a poached egg or a dish of braised cabbage into dinner. Cooking well is not cooking fancy.

Advance Preparation

• •Prepare the Soubise through the sieving step up to 2 days ahead. Press parchment directly against the surface, cover, and refrigerate. Reheat it very gently, then add the cream and mount with the final butter shortly before serving.
• •The base can be frozen before the cream and finishing butter are added. Divide it into small containers, freeze for up to 1 month, thaw overnight in the refrigerator, and reheat slowly before completing the sauce.
• •Finished Soubise keeps for 3 days under refrigeration. Reheat it over low heat with a spoonful of cream, whisking gently; boiling will dull the texture and may release the butter.

Frequently Asked Questions

Nutrition Information

1 serving (about 240g)