Why it works: Onion and tomato are a kitchen classic. They rank in the top 8% of all ingredient pairs, and cooks put them together in 20,633 recipes. Both carry 2-isopropyl-3-methoxypyrazine, which smells earthy, pea. The science ↓
Codfish Toast
Ingredients
Directions
Make the codfish mixture
Fry the sliced onion in butter until soft.
Add the codfish and enough water to cover it.
Stir in the sliced tomatoes and cook for 30 to 45 minutes.
Add a pinch of cayenne to taste.
Serve
Serve the mixture over buttered toast.
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 + tomatotop 8% of all pairsSmell alikemoderateCooked together20,633 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
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Butter + fishtop 12% of all pairsSmell alikemoderateCooked together4,488 recipes
Shared aroma: (z)-4-heptenal (biscuit, cream).
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Onion + buttertop 15% of all pairsSmell alikemoderateCooked together42,912 recipes
Shared aroma: decanal (soap, orange peel).
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Fish + tomatotop 16% of all pairsSmell alikemoderateCooked together213 recipes
Shared aroma: 1-hepten-3-one (metal).
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Onion + fishtop 19% of all pairsSmell alikelowCooked together1,924 recipes
Shared aroma: 2,4-decadienal (seaweed).
Ranks compare each pair with 20,000 random ingredient pairs on CompKitchen. How we score pairs
What each ingredient does
- Codfish
- Provides the main protein and savory flesh that the sauce is built around.
- Onion
- Softened in butter, it adds sweetness and a savory base to the mixture.
- Butter
- Carries the onion's flavor and adds richness to the mixture.
- Fresh tomatoes
- Break down during cooking to add moisture, acidity and body to the mixture.
The step that matters
Cooking the tomatoes for 30 to 45 minutes. Long, gentle cooking breaks the tomatoes down so they thicken the mixture into a cohesive sauce. Stopping too early leaves it watery and chunky, while cooking too hard can dry it out or scorch the bottom of the pan.
Swap the tomato
How well each one fits the dish's main ingredients (onion, butter, fish):
- Potatofits better
- Leekfits better
- Chivefits better
- Tomatothe original
Fit is the average pairing score against onion, butter, fish. 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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