Name: Egg Sauce
Ingredients: 3 ounces butter; 2 tablespoons flour; 2 teaspoons chopped parsley; 1 grated white onion; pepper to taste; ¼ teaspoon coarse sea salt; ¼ teaspoon nutmeg; ½ pint cream or rich milk; optional: pinch of horseradish for serving with fresh fish

Why it works: Parsley and pepper 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 ↓

Egg Sauce

Ingredients

Directions

Melt the butter in a saucepan.
Add flour, parsley, onion, pepper, salt, and nutmeg; mix well.
Stir in the cream or milk and bring to a boil.
Cook for 15 minutes, stirring continually.
If serving with fresh fish, add a pinch of horseradish 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.

Parsley + peppertop 2% of all pairs

Smell alikestrong

Cooked together34,122 recipes

Shared aroma: 4'-methylacetophenone (bitter almond).
Parsley + nutmegtop 3% of all pairs

Smell alikestrong

Cooked together5,062 recipes

Shared aroma: 4'-methylacetophenone (bitter almond).
Parsley + horseradishtop 6% of all pairs

Smell alikestrong

Cooked together562 recipes

Shared aroma: coumarin (sweet, hay).
Onion + horseradishtop 7% of all pairs

Smell alikestrong

Cooked together1,784 recipes

Shared aroma: coumarin (sweet, hay).
Pepper + nutmegtop 7% of all pairs

Smell alikestrong

Cooked together13,015 recipes

Shared aroma: 4'-methylacetophenone (bitter almond).

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

Swap the horseradish

The recipe marks horseradish as optional. How well each one fits the dish's main ingredients (butter, flour, parsley, onion, pepper, nutmeg, cream):

Shallotfits better
Chivefits better
Leekfits better
Horseradishthe original

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