Name: Spinach and Egg Casserole
Ingredients: 1 cup chopped onion; 1 tablespoon butter or margarine; 1 10-ounce package frozen chopped spinach, thawed and drained; 1 cup buttermilk; 2 cups creamed cottage cheese; 3 cups cooked rice; 1 1/2 teaspoons salt; 1/4 teaspoon ground black pepper; 4 eggs, beaten; 1 large fresh tomato, cut into six slices; 1 cup shredded mozzarella cheese

Why it works: Spinach and pepper are a kitchen classic. They rank in the top 6% of all ingredient pairs, and cooks put them together in 3,400 recipes. Both carry nonanal, which smells fat, citrus. 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.

Spinach + peppertop 6% of all pairs

Smell alikemoderate

Cooked together3,400 recipes

Shared aroma: nonanal (fat, citrus).
Onion + spinachtop 8% of all pairs

Smell alikestrong

Cooked together3,336 recipes

Shared aroma: coumarin (sweet, hay).
Spinach + ricetop 8% of all pairs

Smell alikemoderate

Cooked together518 recipes

Shared aroma: 2-methoxy-4-vinylphenol (clove, smoky).
Onion + ricetop 9% of all pairs

Smell alikemoderate

Cooked together10,433 recipes

Shared aroma: 2,4-decadienal (seaweed).
Butter + cottage cheesetop 10% of all pairs

Smell alikemoderate

Cooked together376 recipes

Shared aroma: gamma-decalactone (peach, creamy).

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

What each ingredient does

Eggs: Bind the casserole and set it into a firm, sliceable custard as it bakes.
Cottage cheese: Adds moisture and creamy body, and its proteins help the filling set.
Cooked rice: Provides bulk and structure, soaking up the liquid so the casserole holds its shape.
Buttermilk: Adds moisture and mild acidity, keeping the custard tender.
Mozzarella cheese: Melts over the top and browns, forming a golden, stretchy layer.

The step that matters

Blend in the eggs without overbaking. Eggs set into the custard as they heat. Overbaking or baking at too high a heat makes the casserole dry, rubbery and likely to curdle or weep. Bake only until just set in the center.

Swap the onion

How well each one fits the dish's main ingredients (butter, spinach, buttermilk, cottage cheese, rice, pepper, egg):

Chivefits better
Cucumberfits better
Asparagusfits better
Onionthe original

Fit is the average pairing score against butter, spinach, buttermilk, cottage cheese, rice, pepper, egg. 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.

Ingredient	Portion assumed	kcal
Rice	1 cup cooked (158g) white	206
Milk	1 cup (244ml) whole	149
Butter	1 tbsp (14g)	102
Cottage Cheese	1/2 cup (113g) 2%	98
Mozzarella Cheese	1 oz (28g)	85
Egg	1 large egg (50g)	78
Onion	1 medium (110g)	44
Tomato	1 medium (123g)	22
Spinach	1 cup raw (30g)	7
Black Pepper	1 tsp ground (2.3g)	6
Salt	1 tsp (6g)	0

Spinach and Egg Casserole