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 ↓
Hot-pot
Ingredients
Directions
The book says “a hot oven”. The 400°F (200°C) in the steps is the modern equivalent, not the book's own figure.
Prepare
Preheat the oven to 400°F (200°C).
Peel, wash, and slice the potatoes and onions thinly.
Assemble and bake
Layer the vegetables and tomatoes in a baking dish, dusting with pepper and salt between layers.
Finish with a layer of potatoes on top.
Cut the butter into small pieces and place them on top of the potatoes.
Fill the dish with hot water and bake for 2 hours, adding more hot water if needed.
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.
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Potato + oniontop 3% of all pairsSmell alikemoderateCooked together9,023 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
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Thyme + peppertop 4% of all pairsSmell alikemoderateCooked together11,585 recipes
Shared aroma: beta-phellandrene (minty, terpene).
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Tomato + thymetop 4% of all pairsSmell alikemoderateCooked together2,370 recipes
Shared aroma: 1-octen-3-one (mushroom, metallic).
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Potato + thymetop 5% of all pairsSmell alikemoderateCooked together1,586 recipes
Shared aroma: 1-octen-3-one (mushroom, metallic).
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Potato + tomatotop 5% of all pairsSmell alikestrongCooked together2,798 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
- Potatoes
- Form the bulk of the layers and become tender and starchy as they cook in the water.
- Onions
- Add savoury sweetness and flavour that deepens during the slow bake.
- Tomatoes
- Add acidity and moisture that helps flavour the layers as they cook.
- Butter
- Adds richness and fat that helps the top layer brown and the dish taste rounded.
The step that matters
Adding hot water to the dish. Starting with hot water keeps the bake from stalling in the oven, so the potatoes cook through evenly over the long time. Topping up with water as it evaporates stops the dish from drying out and scorching.
Swap the onion
How well each one fits the dish's main ingredients (potato, tomato, thyme, butter, pepper):
- Capsicumfits better
- Carrotfits better
- Okrafits about as well
- Onionthe original
Fit is the average pairing score against potato, tomato, thyme, 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.
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