Name: Cheese Sandwiches
Ingredients: 1 hard-boiled egg; ¼ pound common cheese, grated; ½ teaspoon coarse sea salt; ½ teaspoon black pepper; ½ teaspoon mustard; 1 tablespoon melted butter; 1 tablespoon vinegar or cold water; 2 biscuits or pieces of oat-cake

Why it works: Mustard and biscuit match in chemistry and in kitchens. They rank in the top 4% of all ingredient pairs, and cooks put them together in 121 recipes. Both carry coumarin, which smells sweet, hay. The science ↓

Cheese Sandwiches

Ingredients

Directions

Prepare

Remove the yolk from the hard-boiled egg and place it in a small bowl.
Crumble the yolk and mix in the melted butter until smooth.

Make the filling

Add the coarse sea salt, black pepper, mustard, and grated cheese, mixing well after each addition.
Stir in the vinegar or cold water to achieve the desired thickness.

Assemble

Spread the mixture between two biscuits or pieces of oat-cake.

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.

Mustard + biscuittop 4% of all pairs

Smell alikestrong

Cooked together121 recipes

Shared aroma: coumarin (sweet, hay).
Mustard + vinegartop 7% of all pairs

Smell alikemoderate

Cooked together14,067 recipes

Shared aroma: isobutyraldehyde (malty, green).
Cheese + buttertop 8% of all pairs

Smell alikemoderate

Cooked together7,962 recipes

Shared aroma: delta-dodecalactone (sweet, creamy).
Pepper + mustardtop 9% of all pairs

Smell alikemoderate

Cooked together15,430 recipes

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

Smell alikemoderate

Cooked together1,805 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).

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

What each ingredient does

Hard-boiled egg yolk: Binds the filling and adds a rich, creamy body.
Common cheese: Provides the main flavour and a savoury, firm-yet-spreadable body.
Melted butter: Adds fat for smoothness and a richer mouthfeel.
Vinegar or cold water: Loosens the mixture to the desired spreadable thickness, with vinegar adding slight acidity.

“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.