Name: Spanish Omelet
Ingredients: 2 onions, finely shredded; 1 green pepper, minced; 1 cup mushrooms, minced; 2 solid tomatoes, cut into small pieces; 2 tablespoons butter; ½ cup tomato sauce; coarse sea salt to taste; black pepper to taste; fancy strips of pimento in oil for garnish

Why it works: Mushroom and tomato are a kitchen classic. They rank in the top 7% of all ingredient pairs, and cooks put them together in 2,719 recipes. Both carry 1-octen-3-one, which smells mushroom, metallic. The science ↓

Spanish Omelet

Ingredients

Directions

In a skillet, melt butter over medium heat.
Add onions, green pepper, mushrooms, and tomatoes; fry for 5 minutes.
Stir in tomato sauce, season with salt and pepper, and reduce until thick.
Pour a spoonful of the mixture into the center of the omelet.
Garnish with a spoonful of the mixture at each end and top with pimento strips.

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.

Mushroom + tomatotop 7% of all pairs

Smell alikemoderate

Cooked together2,719 recipes

Shared aroma: 1-octen-3-one (mushroom, metallic).
Mushroom + buttertop 7% of all pairs

Smell alikemoderate

Cooked together12,525 recipes

Shared aroma: trans-2-decenal (waxy, orange).
Pepper + tomatotop 7% of all pairs

Smell alikemoderate

Cooked together17,923 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
Onion + tomatotop 8% of all pairs

Smell alikemoderate

Cooked together20,633 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
Onion + mushroomtop 10% of all pairs

Smell alikemoderate

Cooked together10,626 recipes

Shared aroma: 2,4-decadienal (seaweed).

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 (pepper, mushroom, tomato, butter, sauce):

Capsicumfits better
Shallotfits about as well
Spinachfits about as well
Onionthe original

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