Name: Onions Baked
Ingredients: large Spanish onions; slightly salted water; butter; salt; 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 ↓

Onions Baked

Oven, in the book's wordsA slow oven

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.

Wash the onions clean without peeling them.
Place the onions in a saucepan with slightly salted water and boil for 1 hour, adding more boiling water as it evaporates.
Drain the onions and lay them on a cloth to dry.
Wrap each onion in buttered tissue paper, twisting the top to secure it.
Bake the wrapped onions in a 300°F (150°C) oven for about 1 hour or until tender.
Peel the onions and place them in a deep dish.
Brown the onions slightly in the oven, basting with butter for 15 minutes.
Season with salt and pepper, then pour melted butter over them.

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.

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.

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).