Name: Baked Onions
Ingredients: large Spanish or Bermuda onions; coarse sea salt; butter; pepper

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

large Spanish or Bermuda onions
coarse sea salt
butter
pepper

Directions

The book gives no oven temperature. The 350°F (175°C) in the steps was added when the recipe was transcribed, as a starting point.

Wash the onions thoroughly without removing the skins.
Boil the onions in salted water for 1 hour, changing the water twice.
Remove the onions and place them on a cloth to evaporate moisture.
Bake the onions in a 350°F (175°C) oven for nearly 1 hour until tender.
Peel the onions and place them in a deep dish.
Brown the onions slightly and baste them freely.
Sprinkle with salt and pepper, then pour melted butter over them before serving.

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.

Onion + peppertop 11% of all pairs

Smell alikemoderate

Cooked together68,474 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
Onion + buttertop 15% of all pairs

Smell alikemoderate

Cooked together42,912 recipes

Shared aroma: decanal (soap, orange peel).
Butter + peppertop 21% of all pairs

Smell alikemoderate

Cooked together85,593 recipes

Shared aroma: trans-2-nonenal (cardboard, fatty).