Name: To Broil Herrings
Ingredients: Herring, scaled and gutted; Flour, for dusting; ½ cup small beer or ale; Whole pepper, to taste; 1 onion, chopped; Butter, for thickening; Flour, for thickening; Mustard, to taste

Why it works: Onion and mustard match in chemistry and in kitchens. They rank in the top 6% of all ingredient pairs, and cooks put them together in 9,259 recipes. Both carry 2-isopropyl-3-methoxypyrazine, which smells earthy, pea. The science ↓

To Broil Herrings

Ingredients

Directions

Scale and gut the herring, cut off their heads, and wash them clean.
Dry the herring with a cloth and dust them with flour.
Broil the herring until cooked through.
In a pot, boil the heads in small beer or ale with whole pepper and chopped onion for 30 minutes.
Strain the mixture, then thicken it with butter, flour, and mustard.
Serve the herring on a dish and pour the sauce into a separate bowl, or serve with melted butter and mustard.

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.

Onion + mustardtop 6% of all pairs

Smell alikestrong

Cooked together9,259 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
Pepper + mustardtop 9% of all pairs

Smell alikemoderate

Cooked together15,430 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
Pepper + oniontop 11% of all pairs

Smell alikemoderate

Cooked together68,474 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
Beer + mustardtop 11% of all pairs

Smell alikemoderate

Cooked together314 recipes

Shared aroma: guaiacol (smoky, sweet).
Flour + buttertop 12% of all pairs

Smell alikelow

Cooked together124,287 recipes

Shared aroma: isobutyraldehyde (malty, green).

Flour and butter 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

Swap the onion

How well each one fits the dish's main ingredients (flour, beer, pepper, butter, mustard):

Horseradishfits better
Shallotfits better
Chivefits better
Onionthe original

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