Why it works: Onion and olive are a kitchen classic. They rank in the top 8% of all ingredient pairs, and cooks put them together in 29,779 recipes. Both carry 2,4-decadienal, which smells seaweed. The science ↓
Onion Confit
Ingredients
Directions
Prepare
Place onions in the feed tube of a food processor and slice, using very light pressure on the pusher.
Combine all ingredients in a skillet with a tight-fitting lid and cook over medium heat.
Cook the onions
Stir onions every 10 minutes, or until deep golden brown and very soft, about 45 minutes.
Cool and serve
Cool and refrigerate.
To serve, try topping 1 cup soft polenta with 1/2 cup confit and crumbled gorgonzola; topping 1/4 seasoned roasted eggplant with 2 ounces goat cheese and 1/2 cup confit; or filling an 8-inch tart shell with 2 cups confit, 2 cups shredded cheddar cheese and tomato slices.
Nutrition, whole recipe (rough)
What these numbers assume: 5 portions
| Ingredient | Portion assumed | kcal |
|---|---|---|
| Olive Oil | 1 tbsp (14g) | 119 |
| Sugar | 1 tbsp (12.5g) granulated | 49 |
| Onion | 1 medium (110g) | 44 |
| Black Pepper | 1 tsp ground (2.3g) | 6 |
| Salt | 1 tsp (6g) | 0 |
One typical portion per ingredient; the recipe's quantities are not counted. A rough guide only, not for medical or dietary planning.
Steps grouped into stages for easier reading; the method is the source's own.
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 + olivetop 8% of all pairsSmell alikemoderateCooked together29,779 recipes
Shared aroma: 2,4-decadienal (seaweed).
-
Onion + peppertop 11% of all pairsSmell alikemoderateCooked together68,474 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
-
Olive + peppertop 11% of all pairsSmell alikemoderateCooked together30,263 recipes
Shared aroma: 2,4-decadienal (seaweed).
-
Pepper + sugartop 32% of all pairsSmell alikelowCooked together19,401 recipes
Shared aroma: 2-nonenal (fatty, green).
-
Olive + sugartop 35% of all pairsSmell alikelowCooked together12,483 recipes
Shared aroma: 1-penten-3-one (fish, pungent).
Pepper and sugar barely smell alike, yet cooks put them together in 19,401 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
- Yellow onions
- Break down slowly into sweet, soft, deeply browned confit as the main ingredient.
- Olive oil
- Carries heat evenly and softens the onions while keeping them moist.
- Sugar
- Caramelizes with the onions' natural sugars, adding sweetness and browning.
The step that matters
Slow cooking to deep golden brown. Cooking over medium heat with occasional stirring lets water evaporate gradually and onion sugars caramelize. Rushing with high heat can scorch the onions before they soften, leaving bitter flavor instead of sweet, mellow depth.
Swap the onion
How well each one fits the dish's main ingredients (olive, pepper, sugar):
- Capsicumfits better
- Tomatofits better
- Eggplantfits better
- Onionthe original
Fit is the average pairing score against olive, pepper, sugar. 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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