Why it works: Onion and potato 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 ↓
Shepherd's Pie with Potato Crust
Ingredients
Directions
The book says “a slow oven”. The 350°F (175°C) in the steps is the modern equivalent, not the book's own figure.
Prepare
Preheat the oven to 350°F (175°C).
Grease a pudding dish with butter.
Chop the cold meat and place it in the dish.
Season with salt and pepper.
Make the gravy
In a pan, melt butter and sauté the chopped onion until soft.
Add the stock and flour, stirring until smooth.
Pour the mixture over the meat in the dish.
Top and bake
Top with the mashed potatoes, spreading evenly.
Bake in the oven for 30-40 minutes until golden brown.
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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Onion + potatotop 3% of all pairsSmell alikemoderateCooked together9,023 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
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Pepper + potatotop 9% of all pairsSmell alikemoderateCooked together8,305 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
-
Pepper + oniontop 11% of all pairsSmell alikemoderateCooked together68,474 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
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Butter + flourtop 12% of all pairsSmell alikelowCooked together124,287 recipes
Shared aroma: isobutyraldehyde (malty, green).
-
Butter + potatotop 13% of all pairsSmell alikemoderateCooked together6,456 recipes
Shared aroma: (z)-4-heptenal (biscuit, cream).
Butter and flour barely smell alike, yet cooks put them together in 124,287 recipes: they work on texture and structure more than aroma.
Ranks compare each pair with 20,000 random ingredient pairs on CompKitchen. How we score pairs
What each ingredient does
- Cold meat
- Forms the main filling, providing the savory bulk of the pie.
- Flour
- Thickens the stock into a smooth gravy that holds the filling together.
- Onion
- Softens while sautéing, adding sweetness and aroma to the filling.
- Boiled and mashed potatoes
- Forms a soft topping that browns in the oven, adding structure and texture.
- Stock
- Provides liquid that becomes the gravy, adding moisture and savory flavor.
The step that matters
Make the gravy smooth before pouring. Adding flour to hot stock can form lumps if not stirred constantly; flour must be fully dispersed so it thickens evenly and the filling stays smooth.
Swap the onion
How well each one fits the dish's main ingredients (meat, pepper, butter, flour, potato):
- Chivefits better
- Shallotfits about as well
- Asparagusfits about as well
- Onionthe original
Fit is the average pairing score against meat, pepper, butter, flour, potato. 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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