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Make your own rich, sticky onion gravy in your slow cooker or crockpot! Perfect with Bangers & Mash or Toad in the Hole, we love it with our nut roast and it's so much tastier than gravy granules.

Slow Cooker Onion Gravy

Slow Cooker Onion Gravy – Make your own rich, sticky onion gravy in your Crock Pot. Perfect with Bangers & Mash, Toad in the Hole or a tasty nut roast! Naturally vegetarian and gluten free. Keywords
5 from 20 votes
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Course: Main Course
Cuisine: British
Prep Time: 10 minutes
Cook Time: 7 hours
Total Time: 7 hours 10 minutes
Servings: 10 people
Calories: 109kcal
Author: Sarah James


  • Slow Cooker or CrockPot


  • 1 kg about 10 medium onions
  • 3 tablespoons vegetable oil
  • 3 tablespoons butter
  • 2 teaspoons salt
  • 1 teaspoon freshly ground black pepper
  • 125 ml dry white wine
  • 500 ml good quality vegetable or beef hot stock (I used Marigold Swiss Bouillon)
  • 2 tablespoons Balsamic vinegar
  • 1 teaspoon Dijon mustard
  • 2 teaspoons freshly chopped thyme
  • 2 tablespoons cornflour / cornstarch mixed with a little water
  • Optional: 1 tablespoon soy sauce


  • Peel and thinly slice onions.
  • Grease the inside of your slow cooker pot and add the onions, oil, butter and salt and pepper.
  • Stir and place on the lid.
  • Cook on low for at least 6 hours (8 hours if you have the time) to caramelise the onions.
  • Once your onions are caramelised, add the wine, hot stock, balsamic vinegar, Dijon mustard and thyme and give it a good stir.
  • Turn your slow cooker to high and whisk in the cornflour water mix.
  • Replace the lid on your slow cooker but this time prop open the lid with a wooden spoon or spatula.
  • Cook on high for 1 to 2 hours.
  • Ladle your onion gravy into a jug or gravy boat.


Makes approx 1 litre - a serving is 100 ml
I've used brown onions but you can easily substitute red onions or shallots. Both will give a sweeter flavour profile to your finished gravy.
Substitute with your favourite stock to make a beef or chicken gravy.
I've used white wine but red wine works well , particularly with red onions.
Add a tablespoon of redcurrant jelly for extra fruity sweetness.
Slow Cooker Onion Gravy will keep in the fridge for up to four days.
Reheat in a pan on the stovetop on a medium heat for about 5 minutes, stirring occasionally.
Slow Cooker Onion Gravy freezes well.
Nutrition information is approximate and meant as a guideline only.
Calories: 109kcal | Carbohydrates: 13g | Protein: 1g | Fat: 8g | Saturated Fat: 6g | Polyunsaturated Fat: 1g | Monounsaturated Fat: 1g | Cholesterol: 9mg | Sodium: 306mg | Potassium: 105mg | Fiber: 2g | Sugar: 5g | Vitamin A: 234IU | Vitamin C: 8mg | Calcium: 29mg | Iron: 1mg