Name: Cheese Omelette, or Welsh Rare-bit
Ingredients: ½ pound good rich cheese, sliced; ⅔ pint new milk; 4 eggs; 3 slices bread, toasted; Butter, for spreading; Mustard, mixed with cold water; Salt, to taste

Why it works: Bread and butter 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 Omelette, or Welsh Rare-bit

Ingredients

Directions

Make the cheese sauce

In a pan, combine the cheese and milk over medium heat.
Stir the cheese and milk occasionally until the cheese is fully dissolved.
Beat the eggs until light and set aside.
Stir in the beaten eggs and continue stirring until the mixture thickens.

Assemble and serve

Spread butter and a thin layer of mustard on the toasted bread.
Pour the cheese and egg mixture over the toast and season with salt.
Serve the omelette on a shallow dish.

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.

Bread + buttertop 7% of all pairs

Smell alikemoderate

Cooked together27,232 recipes

Shared aroma: delta-decalactone (sweet, creamy).
Milk + buttertop 7% of all pairs

Smell alikemoderate

Cooked together81,283 recipes

Shared aroma: (z)-4-heptenal (biscuit, cream).
Cheese + breadtop 7% of all pairs

Smell alikemoderate

Cooked together2,130 recipes

Shared aroma: delta-decalactone (sweet, creamy).
Cheese + buttertop 8% of all pairs

Smell alikemoderate

Cooked together7,962 recipes

Shared aroma: delta-dodecalactone (sweet, creamy).
Cheese + milktop 10% of all pairs

Smell alikemoderate

Cooked together4,426 recipes

Shared aroma: delta-dodecalactone (sweet, creamy).

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

What each ingredient does

Good rich cheese: Melts into the sauce to provide the main flavour and creamy body.
New milk: Liquid that melts the cheese smoothly into a pourable sauce.
Eggs: Thicken the cheese mixture as they set with gentle heat, giving it body.
Bread: Toasted base that holds the sauce and adds a crisp, absorbent contrast.

The step that matters

Stir in the beaten eggs and continue stirring until the mixture thickens. Egg proteins set when heated, so keeping the heat moderate and stirring constantly prevents curdling and gives a smooth, thick sauce.

Swap the mustard

How well each one fits the dish's main ingredients (cheese, milk, egg, bread, butter):

Potatofits better
Asparagusfits better
Capsicumfits better
Mustardthe original

Fit is the average pairing score against cheese, milk, egg, bread, butter. 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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Cheese Omelette, or Welsh Rare-bit