Why it works: Butter and bread are a kitchen classic. They rank in the top 7% of all ingredient pairs, and cooks put them together in 27,232 recipes. Both carry delta-decalactone, which smells sweet, creamy. The science ↓
Cheese Toast
Ingredients
Directions
The book says “a quick oven”. The 400°F (200°C) in the steps is the modern equivalent, not the book's own figure.
Prepare the topping
In a bowl, mash the butter into the grated cheese.
Season the mixture with cayenne pepper, mustard, and salt.
Beat the egg and mix it into the cheese mixture.
Assemble and bake
Toast slices of bread until golden brown and cut into halves or crescents.
Spread about 1 inch of the mixture on the toast.
Toast under a grill or in a 400°F (200°C) oven until light brown.
Serve hot.
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 their aromas overlap, and how often cooks already put them together.
-
Butter + breadtop 7% of all pairsSmell alikemoderateCooked together27,232 recipes
Shared aroma: delta-decalactone (sweet, creamy).
-
Cheese + breadtop 7% of all pairsSmell alikemoderateCooked together2,130 recipes
Shared aroma: delta-decalactone (sweet, creamy).
-
Cheese + buttertop 8% of all pairsSmell alikemoderateCooked together7,962 recipes
Shared aroma: delta-dodecalactone (sweet, creamy).
-
Mustard + peppertop 9% of all pairsSmell alikemoderateCooked together15,430 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
-
Cheese + mustardtop 11% of all pairsSmell alikemoderateCooked 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
- Grated cheese
- Melts into a rich, savoury topping that browns when heated.
- Butter
- Adds fat and richness, helping the cheese mixture spread and turn smooth.
- Egg
- Binds the cheese mixture so it holds together on the toast instead of running off.
- Made mustard
- Adds sharp, tangy flavour that balances the richness of the cheese.
The step that matters
Toasting the topped bread until light brown. Cheese proteins and sugars brown quickly under high heat, so the topping can scorch before the egg sets. Watching closely keeps it golden rather than burnt.
Swap the mustard
How well each one fits the dish's main ingredients (cheese, egg, pepper, butter, bread):
- Capsicumfits better
- Asparagusfits about as well
- Potatofits about as well
- Mustardthe original
Fit is the average pairing score against cheese, egg, pepper, butter, bread. 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.
More cheese toast recipes
You might also like
The free Flavor Lab newsletter: one surprising pairing a week and the molecular reason it works, in 60 seconds. No spam, unsubscribe anytime.
Prefer an account? Create a free account to save pairings and unlock the full chemistry.

Brown Bread461 recipes
Macaroni and Cheese102 recipes
White Bread80 recipes
Bread Omelette60 recipes