Why it works: Peas and onion are a kitchen classic. They rank in the top 13% of all ingredient pairs, and cooks put them together in 5,460 recipes. Both carry 2-isopropyl-3-methoxypyrazine, which smells earthy, pea. The science ↓
Split Pea Soup
Ingredients
Directions
Prepare
Soak the split peas in cold water and boil until tender, then strain through a sieve.
In a pan, fry the finely chopped onions in butter until soft.
Make the soup and serve
Add the soup vegetables, strained peas, and a little coarse sea salt to the pan.
Boil the mixture for a while.
Serve the soup with diced toast.
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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Peas + oniontop 13% of all pairsSmell alikemoderateCooked together5,460 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
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Butter + oniontop 15% of all pairsSmell alikemoderateCooked together42,912 recipes
Shared aroma: decanal (soap, orange peel).
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Peas + buttertop 16% of all pairsSmell alikemoderateCooked together4,887 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
- Split peas
- Break down as they cook, thickening the soup and giving it body.
- Butter
- Adds richness and carries flavor when used to fry the onions.
- Onions
- Softened in butter, they add sweetness and savory aroma to the base.
The step that matters
Cook the peas until fully tender before straining. Peas that are underdone do not break down fully, so the strained soup stays grainy and thin. Thorough softening lets the starches release and the purée become smooth.
Swap the peas
How well each one fits the dish's main ingredients (butter, onion):
- Sesamefits better
- Peanutfits better
- Almondfits better
- Peasthe original
Fit is the average pairing score against butter, 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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