Name: Gruyere Cheese Sandwiches
Ingredients: thin slices of bread; butter; French mustard; grated Gruyere cheese; white pepper; coarse sea salt; cayenne pepper; parsley for garnish

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 ↓

Gruyere Cheese Sandwiches

Ingredients

Directions

Butter one side of each slice of bread.
Spread the buttered sides with a little French mustard.
Sprinkle grated Gruyere cheese thickly on the mustard.
Season with white pepper, coarse sea salt, and a small amount of cayenne.
Press the two covered sides of the slices together.
Cut the sandwiches into oblongs.
Serve on a napkin or dish paper, garnished with parsley.

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).
Bread + buttertop 7% of all pairs

Smell alikemoderate

Cooked together27,232 recipes

Shared aroma: delta-decalactone (sweet, creamy).
Mustard + parsleytop 8% of all pairs

Smell alikestrong

Cooked together2,588 recipes

Shared aroma: trans-2-hexenal (green, leafy).
Mustard + peppertop 9% of all pairs

Smell alikemoderate

Cooked together15,430 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
Butter + gruyere cheesetop 9% of all pairs

Smell alikemoderate

Cooked together323 recipes

Shared aroma: gamma-decalactone (peach, creamy).

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

Swap the white pepper

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

Thymefits better
Capersfits better
Tarragonfits better
White pepperthe original

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