Name: Summer Squash Gratin
Ingredients: 6 Tbs. (3/4 stick) unsalted butter, plus more for greasing pan; 1/3 cup all-purpose flour; 3 cups half-and-half; 1 bay leaf; 1 Tbs. minced garlic; Kosher salt and freshly ground pepper, to taste; 2 tsp. chopped fresh thyme; 3 Tbs. chopped fresh flat-leaf parsley; 1 Tbs. olive oil; 1 yellow onion, thinly sliced; 5 zucchini, about 1 1/2 lb. total, peeled into wide, thin sheets; 6 yellow squash, about 1 1/2 lb. total, peeled into wide, thin sheets; 2 russet potatoes, skin peeled and discarded, potatoes peeled into; wide, thin sheets; 1 cup finely grated Parmigiano-Reggiano cheese

Why it works: Thyme and parsley match in chemistry and in kitchens. They rank in the top 1% of all ingredient pairs, and cooks put them together in 9,057 recipes. Both carry cuminaldehyde, which smells Spicy, cumin. 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.

Thyme + parsleytop 1% of all pairs

Smell alikestrong

Cooked together9,057 recipes

Shared aroma: cuminaldehyde (Spicy, cumin).
Garlic + oniontop 1% of all pairs

Smell alikestrong

Cooked together29,058 recipes

Shared aroma: furaneol (caramel, strawberry).
Pepper + parsleytop 2% of all pairs

Smell alikestrong

Cooked together34,122 recipes

Shared aroma: 4'-methylacetophenone (bitter almond).
Garlic + olivetop 2% of all pairs

Smell alikemoderate

Cooked together25,665 recipes

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

Smell alikemoderate

Cooked together11,585 recipes

Shared aroma: beta-phellandrene (minty, terpene).

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

Swap the onion

How well each one fits the dish's main ingredients (butter, flour, garlic, pepper, thyme, parsley, olive):

Shallotfits better
Chivefits better
Eggplantfits better
Onionthe original

Fit is the average pairing score against butter, flour, garlic, pepper, thyme, parsley, olive. 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
Potato	1 medium (173g) baked	161
Olive Oil	1 tbsp (14g)	119
Cheese	1 oz (28g) cheddar	113
Butter	1 tbsp (14g)	102
Onion	1 medium (110g)	44
Cucumber	1/2 cup sliced (52g)	16
Black Pepper	1 tsp ground (2.3g)	6
Garlic	1 clove (3g)	4
Thyme	1 tsp dried (1.4g)	4
Bay Leaf	1 leaf (0.6g)	2
Parsley	1 tbsp chopped fresh (3.8g)	1
Salt	1 tsp (6g)	0
Pumpkin	not in our table	0

Summer Squash Gratin