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Sauce

Onion Sauce

A sauce made from boiled onions, butter, flour, and white stock, seasoned with salt and pepper.

From an old cookbook · modernised transcription
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Why it works: Onion and pepper are a kitchen classic. They rank in the top 11% of all ingredient pairs, and cooks put them together in 68,474 recipes. Both carry 2-isopropyl-3-methoxypyrazine, which smells earthy, pea. The science ↓

Onion Sauce

Ingredients

Directions

Prepare the onions

  1. Boil the onions in salted water until tender.

Make the sauce

  1. Melt the butter in a saucepan and add the flour, mixing well.

  2. Pour in the white stock and bring to a boil.

  3. Season with salt and pepper.

  4. Press the boiled onions through a sieve and add to the sauce.

  5. Let it boil once more, then remove from heat.

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 + peppertop 11% of all pairs
    Smell alikemoderate
    Cooked together68,474 recipes

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

  2. Butter + flourtop 12% of all pairs
    Smell alikelow
    Cooked together124,287 recipes

    Shared aroma: isobutyraldehyde (malty, green).

  3. Onion + buttertop 15% of all pairs
    Smell alikemoderate
    Cooked together42,912 recipes

    Shared aroma: decanal (soap, orange peel).

  4. Onion + flourtop 17% of all pairs
    Smell alikemoderate
    Cooked together32,460 recipes

    Shared aroma: isobutyraldehyde (malty, green).

  5. Flour + peppertop 19% of all pairs
    Smell alikemoderate
    Cooked together50,459 recipes

    Shared aroma: isobutyraldehyde (malty, green).

Butter and flour barely smell alike, yet cooks put them together in 124,287 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

White onions
Give the sauce its body and mild sweetness once pressed through a sieve.
Butter
Carries the flavour and, with the flour, forms the base of the sauce.
Flour
Thickens the sauce as it cooks with the butter and stock.
White stock
Forms the liquid of the sauce, adding savoury flavour.

The step that matters

Adding the flour to the melted butter. Cooking the flour in the butter, mixed well, cooks out its raw taste and prevents lumps when the stock is added.

Swap the onion

How well each one fits the dish's main ingredients (butter, flour, pepper):

  1. Shallotfits better
  2. Chivefits better
  3. Capsicumfits better
  4. Onionthe original

Fit is the average pairing score against butter, flour, pepper. 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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