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 ↓
Shepherds' Pie
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 potatoes
Grease a deep baking dish with some melted fat from the beef.
Boil or steam the potatoes until tender, then mash and season them.
Spread the mashed potatoes an inch thick on the bottom and sides of the dish.
Layer the fried onions evenly over the potato layer.
Make the filling
Mince the beef and mix it with the jelly from the meat, canned tomatoes, and a little stock or gravy.
Pile the meat mixture in the center of the dish.
Bake and serve
Top with the remaining mashed potatoes, roughing the surface with a fork.
Bake in a moderate oven at 350°F (175°C) for about 45 minutes, until well-browned.
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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Potato + tomatotop 5% of all pairsSmell alikestrongCooked together2,798 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
-
Beef + oniontop 7% of all pairsSmell alikemoderateCooked together17,092 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
-
Tomato + peppertop 7% of all pairsSmell alikemoderateCooked together17,923 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
-
Beef + tomatotop 8% of all pairsSmell alikemoderateCooked together5,448 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
- Beef
- Provides the savory meat base of the filling, with its juices adding richness.
- Potatoes
- Form the mashed topping and base that set and brown in the oven.
- Fried onions
- Add sweetness and savory depth as they cook into the potato layer.
- Canned tomatoes
- Add moisture and acidity to the meat filling.
The step that matters
Roughing the potato topping. Scoring the surface with a fork creates ridges that brown well in the oven, giving a crisp, golden top rather than a pale, flat one.
Swap the onion
How well each one fits the dish's main ingredients (beef, potato, tomato, pepper):
- Capsicumfits better
- Carrotfits about as well
- Onionthe original
- Okrafits about as well
Fit is the average pairing score against beef, potato, tomato, 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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