Name: Omelette a L'espagnole
Ingredients: 6 eggs; 1 small onion or ½ clove of garlic, finely chopped; 3 tablespoons of milk; 1 medium-sized tomato, chopped; ½ pound of bacon, cut into small pieces; ½ teaspoon of flour; Butter the size of a walnut; 5 mushrooms, chopped; Salt and pepper to taste

Why it works: Milk and butter are a kitchen classic. They rank in the top 7% of all ingredient pairs, and cooks put them together in 81,283 recipes. Both carry (z)-4-heptenal, which smells biscuit, cream. The science ↓

Omelette a L'espagnole

Ingredients

Directions

Prepare the filling

Fry the bacon until brown.
Add the tomato, chopped mushrooms, and finely chopped onion or garlic.
Stir over heat for 15 minutes.

Make the omelette

Separate the egg whites and yolks.
Beat the yolks and mix in salt, pepper, flour, and milk.
Gently fold in the beaten egg whites until smooth.
Melt the butter in a frying pan over medium heat.
Pour in the egg mixture.
After a minute or two, loosen the edges with a knife.
When nearly set, pour in the tomato mixture.
Fold the omelet.
Serve on a hot platter.

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.

Milk + buttertop 7% of all pairs

Smell alikemoderate

Cooked together81,283 recipes

Shared aroma: (z)-4-heptenal (biscuit, cream).
Tomato + mushroomtop 7% of all pairs

Smell alikemoderate

Cooked together2,719 recipes

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

Smell alikemoderate

Cooked together12,525 recipes

Shared aroma: trans-2-decenal (waxy, orange).
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

What each ingredient does

Eggs: Whites trapped by folding give the omelette its light, airy structure, while yolks add richness and set firm.
Bacon: Frying renders its fat and browns the pieces, adding savoury flavour to the filling.
Tomato: Cooked down with the filling, it adds moisture and a mild acidity.
Mushrooms: Cooking releases their moisture and concentrates their earthy flavour in the filling.
Onion: Softened by cooking, it adds sweetness and aroma to the filling.
Milk: Its water and proteins loosen the yolk mixture and help it set tender.

The step that matters

Fold in the egg whites gently. Egg whites hold air only while intact. Folding gently keeps that air in the batter, so the omelette stays light rather than deflating.

Swap the onion

How well each one fits the dish's main ingredients (egg, milk, tomato, flour, butter, walnut, mushroom):

Capsicumfits better
Shallotfits better
Asparagusfits better
Onionthe original

Fit is the average pairing score against egg, milk, tomato, flour, butter, walnut, mushroom. 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.

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Mushroom Soup60 recipes

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Omelette a L'espagnole