Name: Squab Pie
Ingredients: 2 lbs neck of mutton; 2 lbs apples, sliced; 1 lb onions, sliced; 1 tablespoon mushroom ketchup; sugar; coarse sea salt; black pepper; boiling water

Why it works: Ketchup and sugar match in chemistry and in kitchens. They rank in the top 8% of all ingredient pairs, and cooks put them together in 260 recipes. Both carry ethanol, which smells alcoholic, ethereal. The science ↓

Squab Pie

Ingredients

Directions

The book gives no oven temperature. The 350°F (175°C) in the steps was added when the recipe was transcribed, as a starting point.

Divide the neck of mutton into 1-inch pieces and place them in a pie dish.
Season the meat well with coarse sea salt and black pepper.
Layer the sliced apples and onions over the meat, sprinkling with sugar.
Fill the dish with boiling water.
Bake in a 350°F (175°C) oven for about 2 hours.
Before serving, pour the gravy out, skim off the fat, add mushroom ketchup, season to taste, and return to the pie.
Serve hot.

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.

Ketchup + sugartop 8% of all pairs

Smell alikestrong

Cooked together260 recipes

Shared aroma: ethanol (alcoholic, ethereal).
Onion + mushroomtop 10% of all pairs

Smell alikemoderate

Cooked together10,626 recipes

Shared aroma: 2,4-decadienal (seaweed).
Onion + peppertop 11% of all pairs

Smell alikemoderate

Cooked together68,474 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
Mushroom + peppertop 11% of all pairs

Smell alikemoderate

Cooked together13,580 recipes

Shared aroma: 2-nonenal (fatty, green).
Mutton + mushroomtop 13% of all pairs

Smell alikemoderate

Cooked together685 recipes

Shared aroma: 1-octen-3-ol (mushroom, earthy).

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

Swap the apple

How well each one fits the dish's main ingredients (mutton, onion, mushroom, ketchup, sugar, pepper):

Lemonfits better
Limefits better
Red currantfits better
Applethe original

Fit is the average pairing score against mutton, onion, mushroom, ketchup, sugar, pepper. Candidates are from the same food group and used in at least 100 recipes.