Name: Lentil Soup
Ingredients: 1 cup brown lentils; 2 cups stock; 1 tablespoon butter; 1 small bay leaf; 1 sprig parsley; 1 small onion, sliced; ½ tablespoon Worcestershire sauce; Salt; Pepper

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 ↓

Lentil Soup

Ingredients

Directions

The book gives no cooking times; the times in the steps were added in transcription, so check for doneness rather than trusting the clock.

Prepare

Rinse the lentils and place them in a pot with the stock.
Add the butter, bay leaf, parsley, and sliced onion.

Cook

Bring to a boil, then reduce heat and simmer for 30 minutes.
Stir in Worcestershire sauce, and season with salt and pepper to taste.

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).
Lentils + parsleytop 5% of all pairs

Smell alikestrong

Cooked together322 recipes

Shared aroma: coumarin (sweet, hay).
Lentils + oniontop 8% of all pairs

Smell alikestrong

Cooked together1,221 recipes

Shared aroma: coumarin (sweet, hay).
Parsley + oniontop 9% of all pairs

Smell alikemoderate

Cooked together25,843 recipes

Shared aroma: 2,4-decadienal (seaweed).
Onion + peppertop 11% of all pairs

Smell alikemoderate

Cooked together68,474 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

Brown lentils: Provide the main body and starch that thicken the soup as they cook.
Stock: Supplies the liquid in which the lentils soften and release flavour.
Butter: Adds fat that carries aroma and gives the soup a rounder mouthfeel.
Onion: Contributes sweetness and savoury depth as it softens in the broth.
Worcestershire sauce: Adds savoury, tangy depth that rounds out the soup's flavour.

Swap the lentils

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

Black-eyed peafits better
Beansfits about as well
Chickpeafits about as well
Lentilsthe original

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

“What each ingredient does” and “The step that matters” were written by Claude from this recipe’s own method and reviewed in samples by CompKitchen.