Why it works: Pepper and lemon match in chemistry and in kitchens. They rank in the top 3% of all ingredient pairs, and cooks put them together in 27,047 recipes. Both carry trans-2-nonenal, which smells cardboard, fatty. The science ↓
Eggs and Onions
Ingredients
Directions
Make the onions
Fry the sliced onions in butter until nicely browned, about 5 minutes.
Sprinkle cayenne pepper over the onions.
Drain the onions from the butter.
Place the onions on a dish before the fire to dry slightly.
Press the lemon juice over the onions.
Poach and serve
Poach the eggs for 3 to 4 minutes.
Lay the poached eggs on top of the onions.
Serve 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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Pepper + lemontop 3% of all pairsSmell alikestrongCooked together27,047 recipes
Shared aroma: trans-2-nonenal (cardboard, fatty).
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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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Onion + buttertop 15% of all pairsSmell alikemoderateCooked together42,912 recipes
Shared aroma: decanal (soap, orange peel).
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Butter + lemontop 16% of all pairsSmell alikemoderateCooked together41,227 recipes
Shared aroma: 3-hexenal (apple, fruity).
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Butter + eggtop 17% of all pairsSmell alikemoderateCooked together118,967 recipes
Shared aroma: decanal (soap, orange peel).
Ranks compare each pair with 20,000 random ingredient pairs on CompKitchen. How we score pairs
What each ingredient does
- Onions
- Browning in butter builds sweet, savoury flavour and forms the base the eggs sit on.
- Eggs
- Set when poached to form the soft, tender top layer of the dish.
- Butter
- Fat that carries heat to brown the onions and adds richness.
- Lemon juice
- Acidity that brightens the rich butter and onions.
The step that matters
Poach the eggs for 3 to 4 minutes. Eggs cook quickly in simmering water, and the white sets around the yolk within minutes. Going past the window leaves the yolk firm, while stopping early leaves the white runny.
Swap the onion
How well each one fits the dish's main ingredients (butter, pepper, lemon, egg):
- Asparagusfits better
- Capsicumfits better
- Spinachfits better
- Onionthe original
Fit is the average pairing score against butter, pepper, lemon, egg. 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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