Name: Onion Sandwich
Ingredients: Bermuda or sweet onion; 2 slices of buttered bread; Salt to taste; Melted or grated cheese; Mayonnaise dressing

Why it works: Bread and cheese are a kitchen classic. They rank in the top 7% of all ingredient pairs, and cooks put them together in 2,130 recipes. Both carry delta-decalactone, which smells sweet, creamy. The science ↓

Onion Sandwich

Ingredients

Directions

Thinly slice the onion and season with salt.
Place the seasoned onion between two slices of buttered bread.
Pour melted or grated cheese over the onion.
Add mayonnaise dressing on top.
Cut the sandwich into rounds.

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.

Bread + cheesetop 7% of all pairs

Smell alikemoderate

Cooked together2,130 recipes

Shared aroma: delta-decalactone (sweet, creamy).
Onion + breadtop 15% of all pairs

Smell alikemoderate

Cooked together8,676 recipes

Shared aroma: 2,4-decadienal (seaweed).
Onion + cheesetop 16% of all pairs

Smell alikemoderate

Cooked together4,849 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).