Name: Portuguese Rice
Ingredients: 1 cup rice; 3 medium-sized onions; 3 tomatoes; 2 oz grated cheese; ½ teaspoon herbs; 2 oz butter; pepper to taste; coarse sea salt to taste

Why it works: Rice and tomato match in chemistry and in kitchens. They rank in the top 6% of all ingredient pairs, and cooks put them together in 3,065 recipes. Both carry trans-2-nonenal, which smells cardboard, fatty. The science ↓

Portuguese Rice

Ingredients

Directions

Prepare the vegetables

Peel and slice the onions and tomatoes.

Cook

Fry the onions and tomatoes in the butter for 15 minutes.
In a pot, bring 2 cups of water to a boil and add the rice.
Add the fried onions, tomatoes, herbs, and seasoning to the rice.
Cook until the rice is soft.

Serve

Serve in a vegetable dish with the grated cheese sprinkled on top.

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.

Rice + tomatotop 6% of all pairs

Smell alikestrong

Cooked together3,065 recipes

Shared aroma: trans-2-nonenal (cardboard, fatty).
Tomato + peppertop 7% of all pairs

Smell alikemoderate

Cooked together17,923 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
Onion + tomatotop 8% of all pairs

Smell alikemoderate

Cooked together20,633 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
Cheese + buttertop 8% of all pairs

Smell alikemoderate

Cooked together7,962 recipes

Shared aroma: delta-dodecalactone (sweet, creamy).
Rice + oniontop 9% of all pairs

Smell alikemoderate

Cooked together10,433 recipes

Shared aroma: 2,4-decadienal (seaweed).

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

What each ingredient does

Rice: Forms the bulk of the dish and absorbs liquid as it softens.
Onions: Frying softens them and builds sweetness and savory depth.
Tomatoes: Add moisture and acidity that flavour the rice as they cook down.
Butter: Fat for frying that carries flavour and helps the onions brown.
Grated cheese: Melts and adds richness and saltiness on top of the finished dish.

Swap the onion

How well each one fits the dish's main ingredients (rice, tomato, cheese, butter, pepper):

Capsicumfits better
Potatofits better
Asparagusfits about as well
Onionthe original

Fit is the average pairing score against rice, tomato, cheese, butter, pepper. 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.