Why it works: Onion and mustard match in chemistry and in kitchens. They rank in the top 6% of all ingredient pairs, and cooks put them together in 9,259 recipes. Both carry 2-isopropyl-3-methoxypyrazine, which smells earthy, pea. The science ↓
Gravy or Sauce for a Goose
Ingredients
Directions
In a small saucepan, brown the minced onion in the butter.
Once it begins to brown, stir in the flour and cook for 5-6 minutes.
Gradually pour in the brown gravy and let it simmer for 15 minutes.
Strain the sauce, bring it back to a boil, and add the mustard mixed with the port wine.
Season with cayenne and salt if needed, and serve very hot.
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 + mustardtop 6% of all pairsSmell alikestrongCooked together9,259 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
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Mustard + peppertop 9% of all pairsSmell alikemoderateCooked together15,430 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
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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 + mustardtop 13% of all pairsSmell alikemoderateCooked together5,066 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
- Onion
- Browning in butter builds a sweet, savoury base for the gravy.
- Butter
- Carries the onion and adds richness and browning flavour.
- Flour
- Cooking it with the fats thickens the gravy as it simmers.
- Brown gravy
- Forms the body of the sauce, providing most of the liquid and savoury flavour.
- Made mustard
- Adds a sharp, tangy note that balances the richness.
- Port wine
- Contributes sweetness, depth and aroma to the finished sauce.
The step that matters
Cooking the flour in the onion and butter. Flour must cook long enough to lose its raw starchy taste, but not so long it darkens too much. Stirring constantly keeps it from scorching and lumping, and it thickens the sauce evenly as the liquid is added.
Swap the onion
How well each one fits the dish's main ingredients (butter, flour, mustard, port wine, pepper):
- Shallotfits better
- Horseradishfits better
- Chivefits better
- Onionthe original
Fit is the average pairing score against butter, flour, mustard, port wine, 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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