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 ↓
Pieds De Mouton Au Sauce Robert
Ingredients
Directions
Prepare
Slice the onion and place it in a stewpan with butter.
Cook the onion until half done.
Cook and finish
Add the trotters and moisten with stock and cullis.
Season well and cook until done.
Stir in mustard and vinegar before serving with a thick 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 + mustardtop 6% of all pairsSmell alikestrongCooked together9,259 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
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Mustard + vinegartop 7% of all pairsSmell alikemoderateCooked together14,067 recipes
Shared aroma: isobutyraldehyde (malty, green).
-
Sauce + mustardtop 13% of all pairsSmell alikemoderateCooked together2,120 recipes
Shared aroma: ethanol (alcoholic, ethereal).
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Onion + vinegartop 14% of all pairsSmell alikemoderateCooked together18,226 recipes
Shared aroma: acetic acid (sour, vinegar).
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Butter + saucetop 15% of all pairsSmell alikelowCooked together15,338 recipes
Shared aroma: ethanol (alcoholic, ethereal).
Butter and sauce barely smell alike, yet cooks put them together in 15,338 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
- Lamb trotters
- Provide the meat and gelatinous body that gives the finished dish its richness.
- Butter
- Carries the onion's flavour and helps it soften and brown gently at the start.
- Onion
- Builds a sweet, savoury aromatic base for the sauce.
- Cullis
- Thickens the liquid into a sauce that clings to the trotters.
- Stock
- Adds moisture and savoury depth as the trotters cook.
- Mustard
- Adds sharp pungency that cuts through the richness of the sauce.
The step that matters
Stir in mustard and vinegar before serving. Acid and mustard are added at the end because long cooking dulls their sharpness. Adding them too early loses the bright flavour that balances the rich sauce.
Swap the onion
How well each one fits the dish's main ingredients (butter, sauce, mustard, vinegar):
- Horseradishfits better
- Shallotfits better
- Radishfits better
- Onionthe original
Fit is the average pairing score against butter, sauce, mustard, vinegar. 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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