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Sauce

Sauce Robert

A creamy onion sauce made with butter, vinegar, Espagnole sauce, and mustard.

From an old cookbook · modernised transcription
From a historical cookbook (Internet Archive) · 5 ingredients
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Why it works: Onion and mustard match in chemistry and in kitchens. They rank in the top 6% of all ingredient pairs, and cooks put them together in 9,259 recipes. Both carry 2-isopropyl-3-methoxypyrazine, which smells earthy, pea. The science ↓

Sauce Robert

Ingredients

Directions

  1. Brown diced onions lightly in butter over medium heat in a pan.

  2. Gradually moisten onions with vinegar, then add Espagnole sauce until creamy thickness.

  3. If sauce too thick, add a little more vinegar or lemon juice.

  4. Remove pan from heat and stir in mustard. Mix well and serve.

Recipe from a historical cookbook (Internet Archive).

Transcribed from a scanned cookbook and modernised for today's kitchens. Where the book gave no heat or time, or said "a moderate oven", the temperatures and times here may be modern equivalents rather than the book's own figures.

Explore the science

The flavor team

The pairs that carry this dish. Each one is judged two ways: how much their aromas overlap, and how often cooks already put them together.

  1. Onion + mustardtop 6% of all pairs
    Smell alikestrong
    Cooked together9,259 recipes

    Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).

  2. Vinegar + mustardtop 7% of all pairs
    Smell alikemoderate
    Cooked together14,067 recipes

    Shared aroma: isobutyraldehyde (malty, green).

  3. Sauce + mustardtop 13% of all pairs
    Smell alikemoderate
    Cooked together2,120 recipes

    Shared aroma: ethanol (alcoholic, ethereal).

  4. Onion + vinegartop 14% of all pairs
    Smell alikemoderate
    Cooked together18,226 recipes

    Shared aroma: acetic acid (sour, vinegar).

  5. Butter + saucetop 15% of all pairs
    Smell alikelow
    Cooked together15,338 recipes

    Shared aroma: ethanol (alcoholic, ethereal).

Butter and sauce barely smell alike, yet cooks put them together in 15,338 recipes: they work on texture and structure more than aroma.

Ranks compare each pair with 20,000 random ingredient pairs on CompKitchen. How we score pairs

What each ingredient does

Onions
Browned slowly in butter to build sweetness and a savory base for the sauce.
Butter
Fat that browns the onions and adds richness to the finished sauce.
Vinegar
Adds acidity that balances the rich Espagnole and sharpens the flavor.
Espagnole sauce
Brown sauce base that gives the sauce body, color and savory depth.
Mustard
Adds sharp, pungent flavor that cuts through the richness of the sauce.

The step that matters

Adding the Espagnole sauce gradually while moisten. Moistening the onions with vinegar first and then adding the Espagnole sauce gradually helps the sauce reach a smooth, creamy thickness without becoming lumpy or too thick.

Swap the onion

How well each one fits the dish's main ingredients (butter, vinegar, sauce, mustard):

  1. Horseradishfits better
  2. Shallotfits better
  3. Radishfits better
  4. Onionthe original

Fit is the average pairing score against butter, vinegar, sauce, mustard. Candidates are from the same food group and used in at least 100 recipes.

“What each ingredient does” and “The step that matters” were written by Claude from this recipe’s own method and reviewed in samples by CompKitchen.

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