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 ↓
Potatoes Au Gratin
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.
Make the sauce
Melt the butter in a saucepan over medium heat.
Add the flour and stir until combined.
Gradually add the milk, stirring until boiling.
Remove from heat and mix in the egg yolks, cheese, salt, and pepper.
Assemble and bake
Layer some of the sauce in a baking dish, followed by a layer of potatoes.
Repeat the layers until the dish is filled.
Top with fine bread crumbs and bake in a 400°F (200°C) oven until browned.
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.
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Butter + breadtop 7% of all pairsSmell alikemoderateCooked together27,232 recipes
Shared aroma: delta-decalactone (sweet, creamy).
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Butter + milktop 7% of all pairsSmell alikemoderateCooked together81,283 recipes
Shared aroma: (z)-4-heptenal (biscuit, cream).
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Cheese + breadtop 7% of all pairsSmell alikemoderateCooked together2,130 recipes
Shared aroma: delta-decalactone (sweet, creamy).
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Butter + cheesetop 8% of all pairsSmell alikemoderateCooked together7,962 recipes
Shared aroma: delta-dodecalactone (sweet, creamy).
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Potato + peppertop 9% of all pairsSmell alikemoderateCooked together8,305 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
- Potatoes
- Form the bulk of the dish and provide its hearty, tender body.
- Butter
- Enriches the sauce and adds flavor and richness.
- Flour
- Thickens the milk into a smooth sauce that holds the layers together.
- Milk
- Forms the liquid base of the sauce, which thickens as it comes to a boil.
- Egg yolks
- Add richness and help set the sauce into a creamy, custard-like texture.
- Cheese
- Adds savory flavor and helps the topping brown as it bakes.
The step that matters
Bring the sauce to a boil while stirring. Flour thickens only when heated enough with liquid, and stirring prevents lumps. Egg yolks are added after removing from heat, because high heat can scramble them and make the sauce grainy.
Swap the potato
How well each one fits the dish's main ingredients (butter, flour, milk, egg, cheese, pepper, bread):
- Capsicumfits about as well
- Potatothe original
- Asparagusfits about as well
- Chivefits about as well
Fit is the average pairing score against butter, flour, milk, egg, cheese, pepper, 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.
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