Skip to main content
Main

Onion Sauce

A savory sauce made from onions, butter, flour, and milk, served with meat.

From an old cookbook · modernised transcription
From a historical cookbook (Internet Archive) · 7 ingredients
Jump to recipe ↓

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 ↓

Onion Sauce

Ingredients

Directions

Prepare

  1. Peel and slice the onions.

Make the sauce

  1. In a saucepan, melt the butter over low heat.

  2. Add the onions, salt, sugar, and pepper; simmer until the onions are soft and pulpy, stirring occasionally.

  3. Stir in the flour and cook for a minute.

  4. Gradually add the milk, stirring constantly until the sauce thickens.

Serve

  1. Serve with mutton cutlets, chops, boiled rabbits, or fowl.

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.

  1. Butter + milktop 7% of all pairs
    Smell alikemoderate
    Cooked together81,283 recipes

    Shared aroma: (z)-4-heptenal (biscuit, cream).

  2. Onion + peppertop 11% of all pairs
    Smell alikemoderate
    Cooked together68,474 recipes

    Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).

  3. Butter + flourtop 12% of all pairs
    Smell alikelow
    Cooked together124,287 recipes

    Shared aroma: isobutyraldehyde (malty, green).

  4. Flour + milktop 14% of all pairs
    Smell alikelow
    Cooked together78,219 recipes

    Shared aroma: isobutyraldehyde (malty, green).

  5. Sugar + flourtop 15% of all pairs
    Smell alikemoderate
    Cooked together92,116 recipes

    Shared aroma: phenylacetaldehyde (hawthorne, honey).

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

Onions
Soften into a pulpy base that gives the sauce its body and sweet flavor.
Butter
Carries the onions as they cook gently and adds richness to the sauce.
Flour
Thickens the milk into a smooth sauce as it cooks with the butter.
Milk
Forms the liquid base that thickens into the creamy sauce.

The step that matters

Adding the milk gradually while stirring. Adding milk slowly and stirring constantly keeps the flour evenly dispersed, so the sauce thickens smoothly without lumps.

Swap the onion

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

  1. Capsicumfits better
  2. Potatofits better
  3. Sweet potatofits better
  4. Onionthe original

Fit is the average pairing score against butter, sugar, pepper, flour, milk. 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.

More onion sauce recipes

Brown 49White 27Sage 9Young 8Spanish 5Fried 3 See all 175 →

You might also like

Tomato SoupTomato Soup526 recipesBrown BreadBrown Bread461 recipesMutton BrothMutton Broth292 recipesYorkshire PuddingYorkshire Pudding264 recipes