Name: Watercress Sandwiches
Ingredients: watercress; hard-boiled eggs, chopped fine; coarse sea salt; black pepper; stale loaf of bread; fresh butter; lemon juice

Why it works: Watercress and lemon match in chemistry and in kitchens. They rank in the top 3% of all ingredient pairs, and cooks put them together in 579 recipes. Both carry coumarin, which smells sweet, hay. The science ↓

Watercress Sandwiches

Ingredients

Directions

Wash the watercress thoroughly and dry it in a cloth, pressing out as much moisture as possible.
Mix the chopped hard-boiled eggs with salt and pepper.
Slice the stale loaf into thin slices.
Butter each slice of bread and place small pieces of watercress between them.
Sprinkle a little lemon juice on the cress before placing the top slice.
Press the sandwiches down firmly and cut them into small squares, removing the crusts.

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.

Watercress + lemontop 3% of all pairs

Smell alikestrong

Cooked together579 recipes

Shared aroma: coumarin (sweet, hay).
Pepper + lemontop 3% of all pairs

Smell alikestrong

Cooked together27,047 recipes

Shared aroma: trans-2-nonenal (cardboard, fatty).
Bread + buttertop 7% of all pairs

Smell alikemoderate

Cooked together27,232 recipes

Shared aroma: delta-decalactone (sweet, creamy).
Watercress + peppertop 10% of all pairs

Smell alikemoderate

Cooked together983 recipes

Shared aroma: coumarin (sweet, hay).
Egg + breadtop 13% of all pairs

Smell alikemoderate

Cooked together22,662 recipes

Shared aroma: (e)-2-octenal (fatty, green).