Name: Baked Trout
Ingredients: 1 trout (about 4 pounds); 3 large potatoes; 2 tablespoons butter; 1 teaspoon onion juice; ¾ teaspoon coarse sea salt; ¼ teaspoon black pepper; 2 tablespoons butter (for baking); 6 tomatoes; ½ cup water

Why it works: Potato and onion are a kitchen classic. They rank in the top 3% of all ingredient pairs, and cooks put them together in 9,023 recipes. Both carry 2-isopropyl-3-methoxypyrazine, which smells earthy, pea. The science ↓

Baked Trout

Oven, in the book's wordsA moderate oven

Ingredients

Directions

The book says “a moderate oven”. The 350°F (175°C) in the steps is the modern equivalent, not the book's own figure.

Prepare the filling

Boil the potatoes until tender, then mash them with butter, onion juice, salt, and pepper.

Stuff and arrange

Stuff the trout with the potato mixture and sprinkle the outside with salt and pepper.
Place the trout in a baking dish with butter, tomatoes, and water.

Bake

Bake in a 350°F (175°C) oven for 50 minutes.

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.

Potato + oniontop 3% of all pairs

Smell alikemoderate

Cooked together9,023 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
Potato + tomatotop 5% of all pairs

Smell alikestrong

Cooked together2,798 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
Pepper + tomatotop 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).
Potato + peppertop 9% of all pairs

Smell alikemoderate

Cooked together8,305 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).

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

What each ingredient does

Trout: Forms the main body of the dish, cooking gently in its own juices and the baking liquid.
Potatoes: Mashed starch that absorbs moisture and gives the stuffing a soft, creamy body.
Butter: Adds fat that carries flavour and keeps the fish and stuffing moist as they bake.
Tomatoes: Release acidic juices that add brightness and moisture to the baking dish.

The step that matters

Bake in a 350°F (175°C) oven for 50 minutes. Fish is cooked when its flesh turns opaque and flakes easily; too little time leaves it undercooked, while too much dries it out. The stuffing also needs to be heated through, so check the thickest part of the fish.