Name: Leek Soup
Ingredients: 6 leeks; 3 medium potatoes; 3 quarts water; 2 tablespoons butter; 1 teaspoon chopped parsley; Salt to taste; Pepper to taste

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 ↓

Leek Soup

Ingredients

Directions

Prepare

Wash and trim the leeks, then chop them.
Peel and dice the potatoes.
In a large pot, bring the water to a boil.

Cook and strain

Add the leeks and potatoes, and cook until tender.
Strain the mixture.
Mash the vegetables through a strainer.

Finish

Return the mashed mixture to the pot.
Stir in the butter, parsley, salt, and pepper.

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.

Photo for illustrative purposes only · Contact us to use it

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).
Leek + parsleytop 4% of all pairs

Smell alikestrong

Cooked together759 recipes

Shared aroma: trans-2-hexenal (green, leafy).
Potato + parsleytop 5% of all pairs

Smell alikemoderate

Cooked together2,855 recipes

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

Smell alikemoderate

Cooked together30 recipes

Shared aroma: 1-octen-3-ol (mushroom, earthy).
Potato + peppertop 9% of all pairs

Smell alikemoderate

Cooked together8,305 recipes

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

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

What each ingredient does

Leeks: Provide the main savory flavor and soft body when cooked until tender.
Potatoes: Break down during cooking and mashing to thicken the soup and add body.
Butter: Adds richness and a silky mouthfeel to the finished soup.