Name: Onion Sauce
Ingredients: 6 large white onions; 2 tablespoons butter; ¼ teaspoon coarse sea salt; ½ cup cream

Why it works: Butter and cream are a kitchen classic. They rank in the top 8% of all ingredient pairs, and cooks put them together in 41,516 recipes. Both carry delta-dodecalactone, which smells sweet, creamy. The science ↓

Onion Sauce

Ingredients

6 large white onions
2 tablespoons butter
¼ teaspoon coarse sea salt
½ cup cream

Directions

Prepare the onions

Peel and halve the onions.
Soak them in a pan of water for 30 minutes.

Cook and mash

Boil the onions for 15 minutes until tender.
Drain the water and mash the onions in a bowl.

Finish the sauce

Add butter, salt, and cream; mix well.
Heat the mixture 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.

Butter + creamtop 8% of all pairs

Smell alikemoderate

Cooked together41,516 recipes

Shared aroma: delta-dodecalactone (sweet, creamy).
Onion + buttertop 15% of all pairs

Smell alikemoderate

Cooked together42,912 recipes

Shared aroma: decanal (soap, orange peel).
Onion + creamtop 18% of all pairs

Smell alikelow

Cooked together10,827 recipes

Shared aroma: 2-nonanone (fruity, floral).

Onion and cream barely smell alike, yet cooks put them together in 10,827 recipes: they work on texture and structure more than aroma.

Ranks compare each pair with 20,000 random ingredient pairs on CompKitchen. How we score pairs

What each ingredient does

White onions: Form the bulk of the sauce and provide its sweet, mellow flavour once cooked.
Butter: Adds richness and a smooth, silky mouthfeel to the mashed onions.
Cream: Adds moisture and creaminess, loosening the mash into a smooth sauce.