Name: Parsley Relish
Ingredients: 1 bunch finely minced parsley; 1 grated onion; ½ cup mayonnaise

Why it works: Parsley and onion are a kitchen classic. They rank in the top 9% of all ingredient pairs, and cooks put them together in 25,843 recipes. Both carry 2,4-decadienal, which smells seaweed. The science ↓

Parsley Relish

Ingredients

1 bunch finely minced parsley
1 grated onion
½ cup mayonnaise

Directions

Combine the minced parsley and grated onion in a bowl.
Mix in the mayonnaise until well combined.
Serve with fish, lamb, or game.

Recipe from a historical cookbook (Internet Archive).

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.

Parsley + oniontop 9% of all pairs

Smell alikemoderate

Cooked together25,843 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

Parsley: Provides fresh, herbal aroma and a bright green flavor that cuts through richness.
Onion: Adds sharp, pungent flavor and aroma that balances the mayonnaise.
Mayonnaise: Supplies fat and creaminess, binding the chopped herbs and onion into a spreadable relish.

“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.