Name: Spanish Omelette
Ingredients: 1 large tomato, chopped; 1 small green pepper, chopped; 1 small onion, sliced; 2 teaspoons parsley, chopped; 2 teaspoons celery, chopped; ½ can mushrooms, chopped

Why it works: Parsley and celery match in chemistry and in kitchens. They rank in the top 1% of all ingredient pairs, and cooks put them together in 6,810 recipes. Both carry 4'-methylacetophenone, which smells bitter almond. The science ↓

Spanish Omelette

Ingredients

Directions

In a skillet, cook the tomato, green pepper, onion, parsley, celery, and mushrooms together for a few minutes.
Add this mixture to the omelette while it is cooking in the pan.

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 + celerytop 1% of all pairs

Smell alikestrong

Cooked together6,810 recipes

Shared aroma: 4'-methylacetophenone (bitter almond).
Pepper + parsleytop 2% of all pairs

Smell alikestrong

Cooked together34,122 recipes

Shared aroma: 4'-methylacetophenone (bitter almond).
Tomato + celerytop 4% of all pairs

Smell alikemoderate

Cooked together3,377 recipes

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

Smell alikestrong

Cooked together16,012 recipes

Shared aroma: 4'-methylacetophenone (bitter almond).
Tomato + mushroomtop 7% of all pairs

Smell alikemoderate

Cooked together2,719 recipes

Shared aroma: 1-octen-3-one (mushroom, metallic).

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

Swap the onion

How well each one fits the dish's main ingredients (tomato, pepper, parsley, celery, mushroom):

Carrotfits better
Capsicumfits better
Spinachfits better
Onionthe original

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