Why it works: Butter and milk are a kitchen classic. They rank in the top 7% of all ingredient pairs, and cooks put them together in 81,283 recipes. Both carry (z)-4-heptenal, which smells biscuit, cream. The science ↓
Nun's Toast
Ingredients
Directions
Prepare
Cut four or five hard-boiled eggs into thin slices.
Put a piece of butter half the size of an egg in a saucepan.
Make the sauce
When the butter begins to bubble, add a teaspoonful of grated onion.
Let it cook a little without taking color.
Stir in a teaspoonful of flour and a cupful of milk, and stir until smooth.
Add pepper and salt to taste.
Add the sliced eggs to the sauce and let them heat through.
Serve
Prepare neatly trimmed slices of buttered toast.
Pour the mixture over the toast and serve immediately.
Nutrition, whole recipe (rough)
What these numbers assume: 7 portions
| Ingredient | Portion assumed | kcal |
|---|---|---|
| Flour | 1 cup (125g) all-purpose | 455 |
| Milk | 1 cup (244ml) whole | 149 |
| Butter | 1 tbsp (14g) | 102 |
| Egg | 1 large egg (50g) | 78 |
| Onion | 1 medium (110g) | 44 |
| Black Pepper | 1 tsp ground (2.3g) | 6 |
| Salt | 1 tsp (6g) | 0 |
One typical portion per ingredient; the recipe's quantities are not counted. A rough guide only, not for medical or dietary planning.
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. See the original page.
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.
-
Butter + milktop 7% of all pairsSmell alikemoderateCooked together81,283 recipes
Shared aroma: (z)-4-heptenal (biscuit, cream).
-
Onion + peppertop 11% of all pairsSmell alikemoderateCooked together68,474 recipes
Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
-
Butter + flourtop 12% of all pairsSmell alikelowCooked together124,287 recipes
Shared aroma: isobutyraldehyde (malty, green).
-
Flour + milktop 14% of all pairsSmell alikelowCooked together78,219 recipes
Shared aroma: isobutyraldehyde (malty, green).
-
Butter + oniontop 15% of all pairsSmell alikemoderateCooked together42,912 recipes
Shared aroma: decanal (soap, orange peel).
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
- Hard-boiled eggs
- Provide the main body of the dish, adding substance and a soft, tender texture to the sauce.
- Milk
- Forms the liquid base of the sauce, giving it a smooth, creamy consistency once thickened.
- Flour
- Thickens the milk into a smooth sauce as it is cooked with the butter.
- Butter
- Adds richness and flavor, and forms the cooking base for the onion and flour.
- Grated onion
- Adds aromatic flavor to the butter before the milk goes in.
The step that matters
Stir the flour into the butter and onion before adding the milk. Flour must cook briefly in the fat so it blends smoothly; adding it cold or stopping too early can leave lumps and a raw, pasty taste.
Swap the onion
How well each one fits the dish's main ingredients (butter, egg, flour, milk, pepper):
- Capsicumfits better
- Potatofits better
- Asparagusfits better
- Onionthe original
Fit is the average pairing score against butter, egg, flour, milk, 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.
You might also like
Tomato Soup526 recipes
Brown Bread461 recipes
Mutton Broth292 recipes
Yorkshire Pudding264 recipesThe free Flavor Lab newsletter: one surprising pairing a week and the molecular reason it works, in 60 seconds. No spam, unsubscribe anytime.
Prefer an account? Create a free account to save pairings and unlock the full chemistry.