Easy Rich Onion Gravy

Written by
Elaine Lemm
Elaine Lemm is a renowned British food writer, classically trained chef, teacher, and author with over 25 years of experience writing about British food and cooking.
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Elaine Lemm
Updated 03/01/21
Onion Gravy
The Spruce
Prep: 5 mins
Cook: 30 mins
Total: 35 mins
Servings: 16 servings
Nutritional Guidelines (per serving)
43 Calories
3g Fat
3g Carbs
1g Protein
See Full Nutritional Guidelines Hide Full Nutritional Guidelines
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Nutrition Facts
Servings: 16
Amount per serving
Calories 43
% Daily Value*
Total Fat 3g 4%
Saturated Fat 1g 5%
Cholesterol 4mg 1%
Sodium 109mg 5%
Total Carbohydrate 3g 1%
Dietary Fiber 0g 1%
Total Sugars 1g
Protein 1g
Vitamin C 1mg 3%
Calcium 7mg 1%
Iron 0mg 1%
Potassium 104mg 2%
*The % Daily Value (DV) tells you how much a nutrient in a food serving contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.
(Nutrition information is calculated using an ingredient database and should be considered an estimate.)

The combination of sweet onions and a dark rich sauce—which is both sweet and savory—is a classic of both the British and Irish kitchen. Onion gravy is a key component for a comforting and warming meal at home.

This recipe for onion gravy is so quick and simple to make and is perfect with bangers and mash, roast meats, mashed potatoes, slathered on a toad in the hole, or as a filling for Yorkshire puddings.

Ingredients

  • 2 tablespoons oil, vegetable or cold-pressed rapeseed oil

  • 2 tablespoons unsalted butter, room temperature

  • 2 medium red onions, thinly sliced

  • 1 teaspoon granulated sugar

  • 1 teaspoon balsamic vinegar

  • 3 cups beef stock

  • 4 teaspoons cornstarch

  • 4 teaspoons cold water

  • Kosher salt, to taste

  • Freshly ground black pepper, to taste

Steps to Make It

  1. Gather the ingredients.

    Onion gravy ingredients
     The Spruce 

  2. Melt the oil and butter in a large saucepan over a gentle heat to ensure the butter does not burn.

    Butter and oil in a sauce pan
    The Spruce

  3. Add the thinly sliced onions to the pan, stir, and cover with a lid.

    Onions and butter in saucepan
    The Spruce

  4. Cook slowly on low heat for approximately 10 minutes or until the onions are soft and translucent. Take care not to burn them. The onions should not be browned but soft and translucent instead.

    Gently cooked onions in a pan
    The Spruce

  5. Add the sugar and balsamic vinegar to the onions and stir well to ensure the onions are coated. Cover again with the lid and continue to cook for a further 5 minutes, again making sure they don't burn.

    Sautéed onions in a sauce pan
    The Spruce

  6. Add the beef stock to the pan and stir well. Increase the heat and boil gently, uncovered, for 5 minutes.

    Beef stock and onions in a sauce pan
    The Spruce

  7. In a heatproof jar, liquid measuring cup, or bowl, mix the cornstarch with the cold water to create a thin, lump-free paste.

    Cornstarch and water mixture in a jar
    The Spruce

  8. Pour a little of the hot gravy into the starch mixture and shake or mix thoroughly.

    Gravy and starch mixture in a mug
    The Spruce 

  9. Pour the starch mixture back into the gravy. Raise the heat to high and boil hard for 10 minutes, or until the gravy is slightly thickened. 

    Gravy mixture boiling in a sauce pan
    The Spruce

  10. Season with salt and pepper and keep warm until ready to serve.

    Finished onion gravy with seasoning in a pan
    The Spruce

Recipe Variations

  • For an onion gravy with a little extra flavor, add a few pinches of fresh or dried thyme or finely minced rosemary.
  • If you don't have balsamic vinegar handy, use red wine vinegar or swap for malt vinegar for a more traditional flavor.
  • If you prefer a thicker gravy, add more cornstarch (also known as cornflour) slurry and boil for a few more minutes to thicken.
  • To create a shine on the gravy, take 1 teaspoon of ice-cold butter and whisk it into the finished gravy before serving. The butter will add even more flavor and make the sauce glossy.

Tips

  • The best onions for this recipe are red onions because they provide just the right amount of sweetness without making the gravy too cloyingly sweet. If you prefer a slightly sharper flavor, then use a standard yellow onion or even a white onion. You can also use large shallots if you like, which will create a much softer finished gravy.
  • Use high-quality, flavorful beef stock for the richest possible onion gravy.
  • This is such a snap to make, why not make double, even triple the quantity? Use what you need, then freeze the rest in 1-cup portions for up to three months. Simply defrost in a pan or the microwave. 

How Do You Make Brown Gravy From Scratch Without Stock?

Beef stock makes the most flavorful gravy, but you can swap it for bouillon in a pinch. Water simply won't give you enough flavor and will leave you with a boring sauce of plain cooked onions. To make this onion gravy vegetarian, use a high-quality vegetable broth, and swap the butter for vegan margarine for vegan gravy.