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Sauce

Onion Sauce.

A sauce made from sliced onions simmered in milk and water, finished with butter, flour, salt, and cream.

From an old cookbook · modernised transcription
From a historical cookbook (Internet Archive) · 7 ingredients
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Why it works: Milk and butter are a kitchen classic. They rank in the top 7% of all ingredient pairs, and cooks put them together in 81,283 recipes. Both carry (z)-4-heptenal, which smells biscuit, cream. The science ↓

Onion Sauce.

Ingredients

Directions

Prepare the onions

  1. Peel and slice the onions thinly.

  2. Boil the onions in milk and water until tender, about 1 hour.

  3. Drain the onions well using a fine sieve.

  4. Pass the onions through a colander with a wooden spoon.

Finish the sauce

  1. In a clean saucepan, combine the onions with butter, flour, salt, and cream or milk. Mix well and simmer for 5 minutes.

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. Milk + buttertop 7% of all pairs
    Smell alikemoderate
    Cooked together81,283 recipes

    Shared aroma: (z)-4-heptenal (biscuit, cream).

  2. Butter + creamtop 8% of all pairs
    Smell alikemoderate
    Cooked together41,516 recipes

    Shared aroma: delta-dodecalactone (sweet, creamy).

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

    Shared aroma: isobutyraldehyde (malty, green).

  4. Milk + flourtop 14% of all pairs
    Smell alikelow
    Cooked together78,219 recipes

    Shared aroma: isobutyraldehyde (malty, green).

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

    Shared aroma: decanal (soap, orange peel).

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
Form the bulk of the sauce, breaking down into a soft, thick purée.
Milk
Cooks the onions gently and adds richness and body to the sauce.
Butter
Adds fat for a smooth mouthfeel and rich flavour.
Flour
Thickens the sauce so it holds together rather than running thin.
Cream
Adds richness and a smoother, silkier texture to the finished sauce.

The step that matters

Passing the onions through a colander. Pushing the cooked onions through a sieve breaks them into a smooth purée. Leftover lumps or fibrous bits will make the sauce grainy, so press thoroughly.

Swap the onion

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

  1. Potatofits better
  2. Leekfits better
  3. Arrowrootfits better
  4. Onionthe original

Fit is the average pairing score against milk, butter, flour, cream. 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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