Fish + Onion
A good pairing. Cooks put them together in 1,924 recipes, and they share 41 flavor molecules: the top 19% of all ingredient pairs.
Do fish and onion go together?
Yes. 1,924 recipes in our collection combine them, and they share 41 flavor molecules. That places them in the top 19% of every ingredient pair we score.
Why they work
They overlap on 41 flavor molecules: 26% of fish's 158. Among the shared key aromas are 2,4-decadienal (seaweed) and decanal (soap, orange peel). Most of what they share is background chemistry many foods carry, so the overlap does little for the smell.
What each one brings
fish
The fresh, green side. Green notes make up 20% of its labelled aroma molecules, against 8% for onion. It carries 117 molecules onion doesn't have.
onion
The savoury side. Savory notes make up 8% of its labelled aroma molecules, against 0% for fish. It carries 324 molecules fish doesn't have.
Add a third ingredient
- Potato: the best fit for both, top 15% of pairs with fish, top 3% with onion.
- Common carp: top 7% of pairs with fish, top 11% with onion.
- Garlic: top 27% of pairs with fish, top 1% with onion.
- Atlantic herring: top 13% of pairs with fish, top 7% with onion.
Ranked by the average of its two pairing scores. Only foods used in at least 100 recipes are suggested.
Recipes with fish and onion
Almost always mains: 75 of the 85 recipes with a course label are mains.
Can you swap one for the other?
Not really. Each has a lot the other lacks: fish has 117 molecules onion doesn't, and onion has 324 that fish doesn't. Treat them as partners, not stand-ins. This compares flavor only; texture, moisture and the job each does in a dish matter too.
All 41 shared molecules
See every shared molecule grouped by chemical class, with key aromas marked, plus the 117 only in fish and the 324 only in onion.
Fish and onion questions
Do fish and onion go together?
A good pairing. Cooks put them together in 1,924 recipes, and they share 41 flavor molecules: the top 19% of all ingredient pairs.
Why do fish and onion taste good together?
They overlap on 41 flavor molecules: 26% of fish's 158. Among the shared key aromas are 2,4-decadienal (seaweed) and decanal (soap, orange peel). Most of what they share is background chemistry many foods carry, so the overlap does little for the smell.
What goes with fish and onion?
Potato is the best third ingredient: top 15% of pairs with fish and top 3% with onion. Common carp and garlic also fit both.
What can you make with fish and onion?
Almost always mains: 75 of the 85 recipes with a course label are mains. Common dishes include Fish Chowder, Fish Calulu, Fish Tacari, Fish and Vegetable Stew.
Can I use onion instead of fish?
Not really. Each has a lot the other lacks: fish has 117 molecules onion doesn't, and onion has 324 that fish doesn't. Treat them as partners, not stand-ins. This compares flavor only; texture, moisture and the job each does in a dish matter too.
Compare other ingredients
Ranks compare this pair with 20,000 random ingredient pairs on CompKitchen. Molecule counts are what the studies and databases we aggregate have reported for each ingredient: a measure of coverage, not a full census. How we score pairs
Cite this analysis
Compound Kitchen (2026). Compound similarity analysis: Fish vs Onion. https://compkitchen.com/compare/fish-vs-onion. Accessed 2026-11-03.
@misc{compkitchen_compare_compound_similarity_analysis_fish_vs_onion_2026,
title = {Compound similarity analysis: Fish vs Onion},
author = {{Compound Kitchen}},
year = {2026},
url = {https://compkitchen.com/compare/fish-vs-onion},
note = {Accessed: 2026-11-03}
}
Methodology DOI: 10.5281/zenodo.19719459 · CC BY 4.0 · Citations are a request, not a requirement.