Why it works: Onion and peas 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 ↓
Suet Soup
Ingredients
Directions
Make the soup
In a soup pot, melt the butter over medium heat.
Add the sliced onions and fry until they are nicely browned, stirring constantly.
Pour in the cold water and add the washed split peas.
Bring to a boil and simmer for 4 hours.
Finish and serve
Use a potato masher to stir the soup before serving.
Strain the soup through a colander into a tureen.
Serve with tomato ketchup on the side, if desired.
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 + peastop 13% of all pairsSmell alikemoderateCooked together5,460 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
-
Butter + oniontop 15% of all pairsSmell alikemoderateCooked together42,912 recipes
Shared aroma: decanal (soap, orange peel).
-
Butter + peastop 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
- Butter
- Adds fat and richness, and helps the onions brown.
- Onions
- Browning them builds sweetness and savory depth in the soup.
- Split peas
- Break down during long simmering to thicken the soup and give it body.
The step that matters
Simmering the soup for 4 hours. Long, gentle simmering is what softens the split peas fully and lets them thicken the liquid. Too little time leaves the peas firm and the soup thin. A rolling boil can scorch the bottom of the pot, so keep the heat low enough for a gentle simmer.
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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