Why it works: Onion and pepper are a kitchen classic. They rank in the top 11% of all ingredient pairs, and cooks put them together in 68,474 recipes. Both carry 2-isopropyl-3-methoxypyrazine, which smells earthy, pea. The science ↓
Stewed Onions
Ingredients
Directions
Prepare the onions
Remove the skins from the onions.
Soak the onions in cold water.
Place the onions in a saucepan and cover with stock.
Stew slowly for 1 hour if young, or 2 hours if large and old, until tender.
Drain the onions and transfer them to a vegetable dish.
Make the sauce
In a frying pan, melt the butter until browned.
Add the flour and mix well.
Gradually add the ½ pint of stock from boiling the onions, stirring continuously until it boils.
Season with salt and pepper.
Serve
Pour the sauce over the onions and serve.
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 + peppertop 11% of all pairsSmell alikemoderateCooked together68,474 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
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Butter + flourtop 12% of all pairsSmell alikelowCooked together124,287 recipes
Shared aroma: isobutyraldehyde (malty, green).
-
Onion + buttertop 15% of all pairsSmell alikemoderateCooked together42,912 recipes
Shared aroma: decanal (soap, orange peel).
-
Onion + flourtop 17% of all pairsSmell alikemoderateCooked together32,460 recipes
Shared aroma: isobutyraldehyde (malty, green).
-
Flour + peppertop 19% of all pairsSmell alikemoderateCooked together50,459 recipes
Shared aroma: isobutyraldehyde (malty, green).
Butter and flour barely smell alike, yet cooks put them together in 124,287 recipes: they work on texture and structure more than aroma.
Ranks compare each pair with 20,000 random ingredient pairs on CompKitchen. How we score pairs
What each ingredient does
- Onions
- Become tender and mild through slow stewing, forming the dish's main body.
- Butter
- Melted and browned to add a nutty flavour and fat to the sauce.
- Flour
- Mixed with the browned butter and stock to thicken the sauce.
- Stock
- Cooks the onions and, reduced into the flour mixture, forms the sauce's liquid.
The step that matters
Stirring the stock into the roux. Adding the liquid gradually while stirring continuously keeps the flour dispersed, so the sauce thickens smoothly without lumps.
Swap the onion
How well each one fits the dish's main ingredients (butter, flour, pepper):
- Shallotfits better
- Chivefits better
- Capsicumfits better
- Onionthe original
Fit is the average pairing score against butter, flour, pepper. 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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