Why it works: Onion and pepper are a kitchen classic. They rank in the top 11% of all ingredient pairs, and cooks put them together in 68,474 recipes. Both carry 2-isopropyl-3-methoxypyrazine, which smells earthy, pea. The science ↓
Baked Onions
Ingredients
Directions
The book gives no oven temperature. The 400°F (200°C) in the steps was added when the recipe was transcribed, as a starting point.
Prepare
Boil the onions until tender.
Place the onions in a baking pan.
Top each onion with pepper, salt, and a piece of butter or dripping.
Add the water from boiling the onions to the pan.
Bake and serve
Bake at 400°F (200°C) until browned, basting frequently.
Serve very 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.
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.
-
Onion + peppertop 11% of all pairsSmell alikemoderateCooked together68,474 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
-
Onion + buttertop 15% of all pairsSmell alikemoderateCooked together42,912 recipes
Shared aroma: decanal (soap, orange peel).
-
Pepper + buttertop 21% of all pairsSmell alikemoderateCooked together85,593 recipes
Shared aroma: trans-2-nonenal (cardboard, fatty).
Ranks compare each pair with 20,000 random ingredient pairs on CompKitchen. How we score pairs
What each ingredient does
- Onions
- Become tender when boiled, then soften further and brown in the oven as the main vegetable.
- Butter or dripping
- Adds fat that carries flavour and helps the onions brown in the oven.
- Water
- Adds moisture to the pan so the onions steam and do not dry out while baking.
The step that matters
Bake at 400°F (200°C) until browned, basting frequently. Basting spreads the fat and pan liquid over the onions, keeping their surfaces moist and helping them brown evenly rather than dry out or scorch.
Swap the onion
How well each one fits the dish's main ingredients (pepper, butter):
- Capsicumfits better
- Potatofits better
- Carrotfits about as well
- Onionthe original
Fit is the average pairing score against pepper, 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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