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Soup

Leek or Onion Soup

A soup made with leeks or onions, oatmeal or flour, broth, egg yolks, and toasted bread.

From an old cookbook · modernised transcription
From a historical cookbook (Internet Archive) · 7 ingredients
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Why it works: Mutton and bread are a kitchen classic. They rank in the top 12% of all ingredient pairs, and cooks put them together in 1,488 recipes. Both carry delta-decalactone, which smells sweet, creamy. The science ↓

Leek or Onion Soup

Ingredients

Directions

Make the base

  1. Mix oatmeal with cold water until smooth.

  2. Gradually add some broth until fully incorporated.

  3. Boil the mixture with leeks or onions until creamy.

  4. Alternatively, use flour instead of oatmeal and stir vigorously for 5 minutes.

Finish and serve

  1. Before serving, stir in beaten egg yolks mixed with a little broth.

  2. Fry chopped onions in oil or butter, then pour boiling water over the onions.

  3. Serve with seasoned toasted bread.

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. Mutton + breadtop 12% of all pairs
    Smell alikemoderate
    Cooked together1,488 recipes

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

  2. Leek + peppertop 12% of all pairs
    Smell alikemoderate
    Cooked together965 recipes

    Shared aroma: coumarin (sweet, hay).

  3. Leek + breadtop 13% of all pairs
    Smell alikemoderate
    Cooked together279 recipes

    Shared aroma: 1-octen-3-ol (mushroom, earthy).

  4. Egg + breadtop 13% of all pairs
    Smell alikemoderate
    Cooked together22,662 recipes

    Shared aroma: (e)-2-octenal (fatty, green).

  5. Mutton + peppertop 16% of all pairs
    Smell alikelow
    Cooked together5,442 recipes

    Shared aroma: trans-2-nonenal (cardboard, fatty).

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

What each ingredient does

Oatmeal
Thickens the broth into a creamy body as it cooks.
Egg yolks
Enrich the soup and add richness and body when stirred in at the end.
Leeks or onions
Provide the main vegetable flavour and sweetness as they cook in the broth.
Mutton broth
Forms the savoury liquid base of the soup.

The step that matters

Stir in the egg yolks off the heat. Egg yolks thicken by gentle heat and curdle or scramble if boiled, so they should be mixed with a little warm broth first and added just before serving, without returning the soup to a rolling boil.

Swap the leek

How well each one fits the dish's main ingredients (mutton, egg, bread, pepper):

  1. Capsicumfits better
  2. Asparagusfits better
  3. Spinachfits about as well
  4. Leekthe original

Fit is the average pairing score against mutton, egg, bread, 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.

More leek soup recipes

Scotch 9Chicken 4Potato 4Welsh 3 See all 47 →

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