Why it works: Onion and butter are a kitchen classic. They rank in the top 15% of all ingredient pairs, and cooks put them together in 42,912 recipes. Both carry decanal, which smells soap, orange peel. The science ↓
Onion Sauce
Ingredients
Directions
Prepare the onions
Peel the onions and soak them in salted water for 30 minutes to preserve their whiteness.
Place the onions in a saucepan, cover with water, and boil until tender, changing the water after 1 hour if they are strong.
Drain the onions thoroughly, chop them, and rub through a sieve.
Make the sauce
In a separate saucepan, heat the melted butter until boiling, then add the onions and salt.
Stir until the mixture simmers.
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 + buttertop 15% of all pairsSmell alikemoderateCooked together42,912 recipes
Shared aroma: decanal (soap, orange peel).
Ranks compare each pair with 20,000 random ingredient pairs on CompKitchen. How we score pairs
What each ingredient does
- Onions
- Form the bulk of the sauce, and when sieved they give it a smooth, thick body.
- Butter
- Adds richness and a silky mouthfeel that carries the onion flavour.
The step that matters
Boiling the onions until tender. Onions that are under-cooked stay fibrous and will not rub through a sieve smoothly, leaving a grainy sauce. Changing the water removes strong sulphurous compounds that would make the sauce harsh.
“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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