Name: Lyonnaise Potatoes
Ingredients: 1 small onion, thinly sliced; 2 tablespoons butter or dripping; 3 cold boiled potatoes, sliced; 1 tablespoon fresh parsley, finely minced

Why it works: Onion and potato are a kitchen classic. They rank in the top 3% of all ingredient pairs, and cooks put them together in 9,023 recipes. Both carry 2-isopropyl-3-methoxypyrazine, which smells earthy, pea. The science ↓

Lyonnaise Potatoes

Ingredients

1 small onion, thinly sliced
2 tablespoons butter or dripping
3 cold boiled potatoes, sliced
1 tablespoon fresh parsley, finely minced

Directions

Fry the sliced onion in butter or dripping in a chafing dish until soft.
Add the sliced cold boiled potatoes and fry until heated through.
Sprinkle the minced parsley over the potatoes before serving.

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.

Onion + potatotop 3% of all pairs

Smell alikemoderate

Cooked together9,023 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
Potato + parsleytop 5% of all pairs

Smell alikemoderate

Cooked together2,855 recipes

Shared aroma: 4'-methylacetophenone (bitter almond).
Onion + parsleytop 9% of all pairs

Smell alikemoderate

Cooked together25,843 recipes

Shared aroma: 2,4-decadienal (seaweed).
Butter + potatotop 13% of all pairs

Smell alikemoderate

Cooked together6,456 recipes

Shared aroma: (z)-4-heptenal (biscuit, cream).
Onion + buttertop 15% of all pairs

Smell alikemoderate

Cooked together42,912 recipes

Shared aroma: decanal (soap, orange peel).

Ranks compare each pair with 20,000 random ingredient pairs on CompKitchen. How we score pairs

What each ingredient does

Onion: Softens into sweetness as it fries, flavouring the whole dish.
Butter or dripping: Fat for frying that carries flavour and helps the potatoes brown lightly.
Potatoes: Form the body of the dish, crisping slightly where they touch the hot fat.