Why it works: Carrot and onion are a kitchen classic. They rank in the top 6% of all ingredient pairs, and cooks put them together in 21,601 recipes. Both carry 2-isopropyl-3-methoxypyrazine, which smells earthy, pea. The science ↓
Fish Soup
Ingredients
Directions
Make the stock
Cut the fish and bones into small pieces.
Place fish, bones, water, carrot, onion, parsley, mace, and a little salt in a stewpan.
Simmer gently for 20 minutes.
Strain the mixture.
Make the soup
Melt the butter in a stewpan and stir in the flour.
Add the strained stock and milk.
Bring to a boil while stirring.
Simmer for 4 minutes.
Beat the egg yolks and cream together.
Strain the egg yolk mixture into the soup.
Stir by the side of the fire for 2-3 minutes without boiling to prevent curdling.
Add lemon juice.
Season to taste.
Serve.
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.
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Carrot + oniontop 6% of all pairsSmell alikemoderateCooked together21,601 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
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Milk + buttertop 7% of all pairsSmell alikemoderateCooked together81,283 recipes
Shared aroma: (z)-4-heptenal (biscuit, cream).
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Cream + buttertop 8% of all pairsSmell alikemoderateCooked together41,516 recipes
Shared aroma: delta-dodecalactone (sweet, creamy).
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Fish + buttertop 12% of all pairsSmell alikemoderateCooked together4,488 recipes
Shared aroma: (z)-4-heptenal (biscuit, cream).
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Butter + flourtop 12% of all pairsSmell alikelowCooked together124,287 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 fish
- Provides the main flavor and body of the soup as it simmers into the stock.
- Butter and flour
- Form a roux that thickens the milk and stock into a smooth soup.
- Egg yolks
- Enrich and thicken the soup, giving it a silky texture when heated gently.
- Cream
- Adds richness and fat, softening the soup's flavor and mouthfeel.
- Milk
- Adds body and mild sweetness, blending with the stock into a creamy base.
- Lemon juice
- Adds acidity that brightens the flavor of the rich soup.
The step that matters
Stir the egg yolk mixture over gentle heat without boiling. Egg yolks are proteins that curdle when overheated, so the soup must stay below boiling while the yolks thicken it smoothly.
Swap the carrot
How well each one fits the dish's main ingredients (fish, milk, cream, butter, flour, egg, onion):
- Potatofits better
- Leekfits better
- Chivefits better
- Carrotthe original
Fit is the average pairing score against fish, milk, cream, butter, flour, egg, onion. 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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