Name: Butter Sauce for Broiled Mackerel
Ingredients: 1 tablespoon butter; 1 tablespoon flour; 2 cups boiling water; 1 teaspoon salt; ¼ teaspoon white pepper; 1 tablespoon chopped parsley or capers; 3 tablespoons butter, cut into small pieces; Juice of ½ lemon

Why it works: Parsley and lemon match in chemistry and in kitchens. They rank in the top 1% of all ingredient pairs, and cooks put them together in 14,037 recipes. Both carry beta-phellandrene, which smells minty, terpene. The science ↓

Butter Sauce for Broiled Mackerel

Ingredients

Directions

Make the sauce

In a saucepan over medium heat, combine 1 tablespoon of butter and 1 tablespoon of flour; stir until bubbling.
Gradually stir in 2 cups of boiling water until the sauce is smooth.
Season with 1 teaspoon of salt, ¼ teaspoon of white pepper, and 1 tablespoon of chopped parsley or capers.
Boil the sauce for 2 minutes, then add 3 tablespoons of butter, stirring until melted. Do not allow the sauce to boil after adding the butter.

Finish and serve

Once melted, stir in the juice of ½ lemon and serve immediately with the fish.

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 + lemontop 1% of all pairs

Smell alikestrong

Cooked together14,037 recipes

Shared aroma: beta-phellandrene (minty, terpene).
Butter + flourtop 12% of all pairs

Smell alikelow

Cooked together124,287 recipes

Shared aroma: isobutyraldehyde (malty, green).
Flour + parsleytop 12% of all pairs

Smell alikemoderate

Cooked together16,675 recipes

Shared aroma: isobutyraldehyde (malty, green).
White pepper + parsleytop 14% of all pairs

Smell alikelow

Cooked together1,451 recipes

Shared aroma: myrcene (balsamic, herbaceous).
Butter + parsleytop 15% of all pairs

Smell alikemoderate

Cooked together28,563 recipes

Shared aroma: trans-2-hexenal (green, leafy).

Butter and flour barely smell alike, yet cooks put them together in 124,287 recipes: they work on texture and structure more than aroma.

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

What each ingredient does

Butter: Enriches the sauce with fat, giving it a smooth, rich mouthfeel and flavor.
Flour: Thickens the butter and water into a smooth sauce as it cooks.
Lemon juice: Adds acidity that brightens the rich butter and balances the flavor.

The step that matters

Do not boil the sauce after adding the butter. Boiling a butter emulsion can cause it to separate, leaving greasy fat instead of a smooth, cohesive sauce. Keeping it warm but below a boil lets the butter melt in evenly.

Swap the white pepper

How well each one fits the dish's main ingredients (butter, flour, parsley, lemon):

Thymefits better
Marjoramfits better
Capersfits better
White pepperthe original

Fit is the average pairing score against butter, flour, parsley, lemon. 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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Tomato Soup526 recipes

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Mutton Broth292 recipes

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Butter Sauce for Broiled Mackerel