Name: Onion Soup
Ingredients: 2 onions; 4 tomatoes; 2 tablespoons finely ground pine nuts; 1 egg white

Why it works: Onion and tomato are a kitchen classic. They rank in the top 8% of all ingredient pairs, and cooks put them together in 20,633 recipes. Both carry 2-isopropyl-3-methoxypyrazine, which smells earthy, pea. The science ↓

Onion Soup

Ingredients

2 onions
4 tomatoes
2 tablespoons finely ground pine nuts
1 egg white

Directions

Grind the onions finely and press out all the juice.
Add the finely sliced tomatoes, ground pine nuts, and beaten egg white.
Serve with any grain.

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 + tomatotop 8% of all pairs

Smell alikemoderate

Cooked together20,633 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
Tomato + pinetop 11% of all pairs

Smell alikemoderate

Cooked together323 recipes

Shared aroma: 2,3-pentanedione (butter, sweet).
Onion + pinetop 13% of all pairs

Smell alikemoderate

Cooked together587 recipes

Shared aroma: guaiacol (smoky, sweet).
Pine + nutstop 14% of all pairs

Smell alikemoderate

Cooked together15 recipes

Shared aroma: 2,3-pentanedione (butter, sweet).
Onion + nutstop 19% of all pairs

Smell alikemoderate

Cooked together114 recipes

Shared aroma: furaneol (caramel, strawberry).