Name: Lettuce Sandwiches
Ingredients: bread; butter; tartare sauce; lettuce leaves; coarse sea salt; black pepper; parsley sprigs

Why it works: Pepper and parsley match in chemistry and in kitchens. They rank in the top 2% of all ingredient pairs, and cooks put them together in 34,122 recipes. Both carry 4'-methylacetophenone, which smells bitter almond. The science ↓

Lettuce Sandwiches

Ingredients

Directions

Cut thin slices of bread and butter one side lightly.
Spread a thin layer of tartare sauce on the buttered side.
Wash, trim, drain, and shred crisp lettuce leaves.
Place the shredded lettuce on the bread, sprinkle with salt and pepper, and sandwich them together.
Cut into convenient sizes, dish up, and garnish with parsley sprigs.

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.

Pepper + parsleytop 2% of all pairs

Smell alikestrong

Cooked together34,122 recipes

Shared aroma: 4'-methylacetophenone (bitter almond).
Lettuce + parsleytop 5% of all pairs

Smell alikestrong

Cooked together1,483 recipes

Shared aroma: trans-2-hexenal (green, leafy).
Bread + buttertop 7% of all pairs

Smell alikemoderate

Cooked together27,232 recipes

Shared aroma: delta-decalactone (sweet, creamy).
Lettuce + peppertop 9% of all pairs

Smell alikemoderate

Cooked together4,037 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
Butter + saucetop 15% of all pairs

Smell alikelow

Cooked together15,338 recipes

Shared aroma: ethanol (alcoholic, ethereal).

Butter and sauce barely smell alike, yet cooks put them together in 15,338 recipes: they work on texture and structure more than aroma.

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

Swap the lettuce

How well each one fits the dish's main ingredients (bread, butter, sauce, pepper, parsley):

Shallotfits better
Capsicumfits better
Carrotfits better
Lettucethe original

Fit is the average pairing score against bread, butter, sauce, pepper, parsley. Candidates are from the same food group and used in at least 100 recipes.