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 ↓
Scalloped Onions
Ingredients
Directions
The book says “a hot oven”. The 400°F (200°C) in the steps is the modern equivalent, not the book's own figure.
Prepare
Peel the onions and boil them in enough water to cover with 1 teaspoon of salt until tender.
Grate an equal amount of bread crumbs and moisten them with cold milk.
Once the onions are tender, pull them apart with two forks.
Assemble and bake
Layer the onions and moistened bread crumbs in a buttered baking dish, seasoning each layer lightly with salt and pepper.
Top with a layer of bread crumbs and dot with small pieces of butter.
Bake in a hot oven at 400°F (200°C) until the bread crumbs are brown, then 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.
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Bread + buttertop 7% of all pairsSmell alikemoderateCooked together27,232 recipes
Shared aroma: delta-decalactone (sweet, creamy).
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Milk + buttertop 7% of all pairsSmell alikemoderateCooked together81,283 recipes
Shared aroma: (z)-4-heptenal (biscuit, cream).
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Bread + milktop 11% of all pairsSmell alikemoderateCooked together11,466 recipes
Shared aroma: 2-undecenal (sweet).
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Onion + peppertop 11% of all pairsSmell alikemoderateCooked together68,474 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
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Onion + buttertop 15% of all pairsSmell alikemoderateCooked together42,912 recipes
Shared aroma: decanal (soap, orange peel).
Ranks compare each pair with 20,000 random ingredient pairs on CompKitchen. How we score pairs
What each ingredient does
- Onions
- Provide the bulk and soft, sweet body of the dish once boiled until tender.
- Bread crumbs
- Absorb liquid and form a soft layer that browns on top during baking.
- Milk
- Moistens the bread crumbs so they stay tender rather than drying out in the oven.
- Butter
- Adds richness and helps the topping brown as it bakes.
The step that matters
Bake until the crumbs are brown. Baking in a hot oven sets the layers and browns the bread crumb topping; underbaking leaves the top pale and the dish wet inside, while the browning adds flavour and colour.
Swap the onion
How well each one fits the dish's main ingredients (bread, milk, butter, pepper):
- Capsicumfits better
- Potatofits better
- Tomatofits better
- Onionthe original
Fit is the average pairing score against bread, milk, butter, pepper. 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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