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 ↓
Onions
Ingredients
Directions
Boil
Boil the onions in plenty of water with salt for 30 minutes.
Drain the first water and add fresh water.
Boil slowly for 3 hours until tender.
Drain the onions.
Finish with butter
Add butter to the saucepan.
Toss the onions in it over the heat for 5 minutes.
Serve with or without the butter, based on preference.
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.
-
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 dish's main body and become soft, sweet and tender through long boiling.
- Butter
- Adds richness and fat, giving the onions a smooth, savory coating.
The step that matters
Boil slowly for 3 hours until tender. A gentle simmer softens the onions evenly without breaking them apart. A hard boil can make the outer layers mushy while the centre stays firm.
“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.
You might also like
Tomato Soup526 recipes
Brown Bread461 recipes
Mutton Broth292 recipes
Yorkshire Pudding264 recipesThe free Flavor Lab newsletter: one surprising pairing a week and the molecular reason it works, in 60 seconds. No spam, unsubscribe anytime.
Prefer an account? Create a free account to save pairings and unlock the full chemistry.