Why it works: Onion and rice are a kitchen classic. They rank in the top 9% of all ingredient pairs, and cooks put them together in 10,433 recipes. Both carry 2,4-decadienal, which smells seaweed. The science ↓
Onion Soup, Cheap
Ingredients
Directions
Prepare
Cut the onions into small pieces.
In a stewpan, melt the butter and sauté the onions until well cooked.
Make the soup
Mix the rice flour smoothly with the water, then add it to the onions.
Season with salt, pepper, and sugar, and simmer until the onions are tender.
Thicken the soup with a mixture of butter and flour, then 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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Onion + ricetop 9% of all pairsSmell alikemoderateCooked together10,433 recipes
Shared aroma: 2,4-decadienal (seaweed).
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Onion + peppertop 11% of all pairsSmell alikemoderateCooked together68,474 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
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Rice + peppertop 12% of all pairsSmell alikemoderateCooked together8,379 recipes
Shared aroma: trans-2-nonenal (cardboard, fatty).
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Butter + flourtop 12% of all pairsSmell alikelowCooked together124,287 recipes
Shared aroma: isobutyraldehyde (malty, green).
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Flour + sugartop 15% of all pairsSmell alikemoderateCooked together92,116 recipes
Shared aroma: phenylacetaldehyde (hawthorne, honey).
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
- Onions
- Provide the main body and sweet, savory flavor of the soup as they cook down.
- Butter
- Adds fat for sautéing the onions and enriches the soup's flavor and mouthfeel.
- Rice flour
- Thickens the soup as it cooks, giving it a smoother body.
- Powdered sugar
- Adds a touch of sweetness that helps balance and deepen the caramelized onion flavor.
The step that matters
Sauté the onions until well cooked. Slowly cooking the onions in butter drives off moisture and browns their natural sugars, which builds the deep flavor of the soup. Rushing this step leaves the soup tasting raw and flat.
Swap the onion
How well each one fits the dish's main ingredients (butter, rice, flour, pepper, sugar):
- Capsicumfits better
- Sweet potatofits better
- Okrafits better
- Onionthe original
Fit is the average pairing score against butter, rice, flour, pepper, sugar. 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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