Name: Vegetable Soup Without Meat
Ingredients: 2 onions; 2 tablespoons flour; 2 cups water; 2 cups milk; 2 teaspoons butter; 2 slices of bread; 2 hard-boiled eggs

Why it works: Butter and bread are a kitchen classic. They rank in the top 7% of all ingredient pairs, and cooks put them together in 27,232 recipes. Both carry delta-decalactone, which smells sweet, creamy. The science ↓

Vegetable Soup Without Meat

Ingredients

Directions

Prepare the soup

Slice the onions.
Fry the sliced onions until brown.
Add flour to thicken 2 cups of water.
Stir in 2 teaspoons of butter.
Add 2 cups of water and 2 cups of milk.

Finish and serve

Toast the bread until very light brown.
Crush the toasted bread into the soup.
Cover the soup for a few minutes.
Add 2 hard-boiled eggs, chopped finely, just before serving.

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.

Butter + breadtop 7% of all pairs

Smell alikemoderate

Cooked together27,232 recipes

Shared aroma: delta-decalactone (sweet, creamy).
Milk + buttertop 7% of all pairs

Smell alikemoderate

Cooked together81,283 recipes

Shared aroma: (z)-4-heptenal (biscuit, cream).
Milk + breadtop 11% of all pairs

Smell alikemoderate

Cooked together11,466 recipes

Shared aroma: 2-undecenal (sweet).
Flour + buttertop 12% of all pairs

Smell alikelow

Cooked together124,287 recipes

Shared aroma: isobutyraldehyde (malty, green).
Bread + eggtop 13% of all pairs

Smell alikemoderate

Cooked together22,662 recipes

Shared aroma: (e)-2-octenal (fatty, green).

Flour and butter 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

Onions: Browning when fried, adding sweetness and savory depth to the soup base.
Flour: Thickens the liquid into a smooth, body-rich soup as it cooks with the water.
Milk: Adds creaminess and a soft, mellow flavor to the soup.
Butter: Adds richness and fat, carrying flavor and giving a smooth mouthfeel.
Bread: Toasted and crushed into the soup, it thickens the liquid and adds toasty flavor.
Eggs: Chopped hard-boiled eggs add substance and a mild, rich flavor.

The step that matters

Add flour to thicken 2 cups of water. Flour must be fully mixed into the liquid, ideally whisked smooth, so it hydrates evenly. Lumps form when flour is added to hot liquid all at once, and they are hard to remove later.

Swap the onion

How well each one fits the dish's main ingredients (flour, milk, butter, bread, egg):

Asparagusfits better
Leekfits better
Shallotfits better
Onionthe original

Fit is the average pairing score against flour, milk, butter, bread, egg. 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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Vegetable Soup Without Meat