Why it works: Lentils and onion match in chemistry and in kitchens. They rank in the top 8% of all ingredient pairs, and cooks put them together in 1,221 recipes. Both carry coumarin, which smells sweet, hay. The science ↓
Lentil Soup
Ingredients
Directions
Make the soup
Cook lentils in water until tender.
Pass lentils through a coarse sieve.
Chop onion and fry in oil or butter until brown.
Pour lentil soup over the onion and bring to a boil.
Serve
Serve hot.
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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Lentils + oniontop 8% of all pairsSmell alikestrongCooked together1,221 recipes
Shared aroma: coumarin (sweet, hay).
-
Onion + buttertop 15% of all pairsSmell alikemoderateCooked together42,912 recipes
Shared aroma: decanal (soap, orange peel).
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Lentils + buttertop 27% of all pairsSmell alikemoderateCooked together486 recipes
Shared aroma: isobutyraldehyde (malty, green).
Ranks compare each pair with 20,000 random ingredient pairs on CompKitchen. How we score pairs
What each ingredient does
- Lentils
- Break down into a thick, body-giving purée when passed through a sieve.
- Onion
- Browning in fat builds sweet, savoury flavour that carries into the soup.
- Oil or butter
- Fat carries the onion's flavour and helps it brown in the pan.
The step that matters
Frying the onion until brown. Browning the onion in oil or butter develops deep, savoury flavour through the Maillard reaction. Pale onion gives a flatter soup, so cook until it is properly coloured before adding the lentil liquid.
Swap the lentils
How well each one fits the dish's main ingredients (onion, butter):
- Sesamefits better
- Peanutfits better
- Almondfits better
- Lentilsthe original
Fit is the average pairing score against onion, butter. 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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