Name: Kale and Collard Green Gratin
Ingredients: 2 oz. very thinly sliced prosciutto; 1 cup breadcrumbs, coarsely chopped; 4 tablespoons olive oil, divided; 1 teaspoon chopped fresh thyme; 1 cup finely grated Parmesan, divided; Kosher salt and freshly ground black pepper; 1 bunches collard greens (about .5 lb.), center ribs and stems removed; 1 bunch kale (about .5 lb.), center ribs and stems removed; 1 large onion, thinly sliced; 2 garlic cloves, finely chopped; 2 tablespoons unsalted butter; 2 tablespoons all-purpose flour; 2 cups 2% milk or whole; ¼ teaspoon freshly grated nutmeg

Why it works: Onion and garlic match in chemistry and in kitchens. They rank in the top 1% of all ingredient pairs, and cooks put them together in 29,058 recipes. Both carry furaneol, which smells caramel, strawberry. The science ↓

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 + garlictop 1% of all pairs

Smell alikestrong

Cooked together29,058 recipes

Shared aroma: furaneol (caramel, strawberry).
Kale + garlictop 1% of all pairs

Smell alikestrong

Cooked together490 recipes

Shared aroma: coumarin (sweet, hay).
Thyme + clovetop 2% of all pairs

Smell alikestrong

Cooked together4,108 recipes

Shared aroma: cuminaldehyde (Spicy, cumin).
Olive + garlictop 2% of all pairs

Smell alikemoderate

Cooked together25,665 recipes

Shared aroma: linalool (floral, citrus).
Thyme + kaletop 4% of all pairs

Smell alikestrong

Cooked together93 recipes

Shared aroma: coumarin (sweet, hay).

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

Swap the clove

How well each one fits the dish's main ingredients (prosciutto, olive, thyme, pepper, kale, onion, garlic):

Parsleyfits better
Rosemaryfits better
Capersfits better
Clovethe original

Fit is the average pairing score against prosciutto, olive, thyme, pepper, kale, onion, garlic. Candidates are from the same food group and used in at least 100 recipes.

Ingredient	Portion assumed	kcal
Flour	1 cup (125g) all-purpose	455
Milk	1 cup (244ml) whole	149
Olive Oil	1 tbsp (14g)	119
Parmesan Cheese	1 oz (28g)	110
Butter	1 tbsp (14g)	102
Onion	1 medium (110g)	44
Nutmeg	1 tsp ground (2.2g)	12
Collard Greens	1 cup (36g) raw	11
Spinach	1 cup raw (30g)	7
Black Pepper	1 tsp ground (2.3g)	6
Thyme	1 tsp dried (1.4g)	4
Garlic	1 clove (3g)	4
Salt	1 tsp (6g)	0

Kale and Collard Green Gratin