Name: Espagnole or Brown Sauce
Ingredients: 1 oz. butter; 1 oz. flour; ½ pint brown stock; 1 tomato, chopped; 1 onion, chopped; Bouquet of herbs; 2 or 3 mushrooms, sliced; Salt and pepper to taste; Small piece of carrot, chopped

Why it works: Pepper and carrot match in chemistry and in kitchens. They rank in the top 6% of all ingredient pairs, and 14,555 recipes mention both. Both carry 2-isopropyl-3-methoxypyrazine, which smells earthy, pea. The science ↓

Espagnole or Brown Sauce

Ingredients

Directions

In a saucepan, melt the butter over medium heat.
Add the chopped onion and carrot, and fry until softened.
Stir in the sliced mushrooms, flour, salt, and pepper.
Gradually add the brown stock while stirring continuously.
Simmer the mixture for 20 minutes, then strain before serving.

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 aroma chemistry they share, and how many recipes mention both.

Pepper + carrottop 6% of all pairs

Aroma overlapstrong

Mentioned together14,555 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
Tomato + carrottop 6% of all pairs

Aroma overlapstrong

Mentioned together3,606 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
Onion + carrottop 6% of all pairs

Aroma overlapmoderate

Mentioned together21,601 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
Tomato + mushroomtop 7% of all pairs

Aroma overlapmoderate

Mentioned together2,719 recipes

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

Aroma overlapmoderate

Mentioned together12,525 recipes

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

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

What each ingredient does

Butter: Fat that cooks the vegetables and forms the base of the roux.
Flour: Thickens the sauce as it cooks with the butter and stock.
Brown stock: Liquid that gives the sauce its body and savoury flavour.
Onion: Softens and sweetens during frying, adding aromatic depth to the sauce.
Mushrooms: Add earthy savoury flavour as they cook down into the sauce.

The step that matters

Adding the brown stock. Adding stock gradually while stirring continuously keeps the flour smooth, so the sauce thickens evenly without lumps.

Flavor stand-ins for the onion

How well each one fits the dish's main ingredients (butter, flour, tomato, mushroom, pepper, carrot):

Capsicumbetter flavor fit
Spinachbetter flavor fit
Potatobetter flavor fit
Onionthe original

Fit is the average pairing score against butter, flour, tomato, mushroom, pepper, carrot. Candidates are from the same food group and used in at least 100 recipes. This compares flavor only: it does not check the job the ingredient does in the dish (bulk, moisture, acidity, structure).

“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.