Why it works: Onion and butter are a kitchen classic. They rank in the top 15% of all ingredient pairs, and cooks put them together in 42,912 recipes. Both carry decanal, which smells soap, orange peel. The science ↓
Baked Onions
Ingredients
Directions
The book says “a slow oven”. The 300°F (150°C) in the steps is the modern equivalent, not the book's own figure.
Prepare
Wash the onions but do not peel them.
Boil the onions in salted water for 1 hour, changing the water twice.
Once tender, drain the onions on a cloth.
Bake
Wrap each onion in buttered paper, twisting the top closed.
Bake the wrapped onions for 1 hour in a 300°F (150°C) oven.
Finish and serve
Peel and brown the onions before serving.
Serve with melted butter.
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.
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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
- Slowly cooked, they turn soft and sweet, and their flesh becomes the dish's main body.
- Butter
- Coats the wrapping paper and the finished onions, adding fat, richness and moisture.
The step that matters
Peel and brown the onions before serving. Browning comes from the Maillard reaction, which needs direct heat on a dry surface. Onions that are wet or still steamy from the wrapping will soften rather than brown, so the surface may stay pale.
“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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