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 ↓
Walnut Sauce
Ingredients
Directions
Make the sauce
Melt the butter in a saucepan.
Fry the onions until lightly browned.
Sprinkle in the flour and fry slowly until it turns a nut-brown color.
Add the stock and simmer gently for 30 minutes.
Strain the sauce and return it to the saucepan.
Finish and serve
Season with salt and pepper, then add the vinegar and walnuts, diced.
Serve with braised mutton or any dish that requires a sharp sauce.
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).
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Flour + walnuttop 12% of all pairsSmell alikemoderateCooked together5,873 recipes
Shared aroma: isobutyraldehyde (malty, green).
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Walnut + peppertop 13% of all pairsSmell alikemoderateCooked together3,039 recipes
Shared aroma: 2-nonenal (fatty, green).
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Onion + vinegartop 14% of all pairsSmell alikemoderateCooked together18,226 recipes
Shared aroma: acetic acid (sour, vinegar).
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
- Flour
- Thickens the stock into a smooth sauce as it cooks with the butter.
- Butter
- Carries the onions and flour and adds richness to the sauce.
- Onions
- Browning in the butter adds savoury depth and sweetness to the sauce.
- Pickled walnuts
- Add a distinctive tangy, savoury flavour to the finished sauce.
- Walnut vinegar
- Adds sharpness that balances the richness of the butter and flour base.
The step that matters
Frying the flour to nut-brown. Flour cooked slowly in fat toasts gradually, developing colour and nutty flavour. Cooking too fast or too briefly leaves a pale, raw-tasting sauce, or it scorches and turns bitter if overheated.
Swap the walnut
How well each one fits the dish's main ingredients (butter, flour, onion, vinegar, pepper):
- Sesamefits better
- Black-eyed peafits better
- Beansfits better
- Walnutthe original
Fit is the average pairing score against butter, flour, onion, vinegar, 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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