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 ↓
Soubise Sauce, Brown
Ingredients
Directions
Prepare the onions
Peel and wash the onions, then mince them.
Cook and finish the sauce
Fry the minced onions in a stewpan with a little butter until very brown.
Moisten with Spanish sauce, or sprinkle with flour mixed with veal or beef gravy.
Skim off the fat, then season the puree with coarse sea salt and black pepper.
Strain the mixture through a fine sieve to remove onion pieces.
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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Onion + buttertop 15% of all pairsSmell alikemoderateCooked together42,912 recipes
Shared aroma: decanal (soap, orange peel).
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Onion + vealtop 17% of all pairsSmell alikelowCooked together6,841 recipes
Shared aroma: 2,4-decadienal (seaweed).
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Onion + flourtop 17% of all pairsSmell alikemoderateCooked together32,460 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
- Browning them builds sweetness and deep savoury flavour, and they form the puree that becomes the sauce.
- Butter
- Fat for frying that carries flavour and helps the onions brown.
- Flour
- Thickens the sauce, giving it body when mixed with gravy.
- Veal or beef gravy
- Adds savoury meat flavour and liquid to the sauce.
The step that matters
Fry the onions until very brown. Onions must be browned, not just softened. Browning through the Maillard reaction and caramelization builds the deep, sweet flavour the sauce depends on. Stir often so they colour evenly without scorching.
Swap the onion
How well each one fits the dish's main ingredients (butter, flour, veal, pepper):
- Shallotfits better
- Leekfits better
- Capsicumfits better
- Onionthe original
Fit is the average pairing score against butter, flour, veal, 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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