French Onion Soup


June 1, 2018

Rich tasty French Onion Soup, you’d never guess it wasn’t made in the traditional manner.
It is the easiest thing you’ll ever make in your slow cooker - and the result is simply stunning! It’s incredible how the onions caremelise all by themselves!

  • Prep: 30 mins
  • Cook: 12 hrs
  • Yields: 6-8 generous starters


1.5 Kgs Onions peeled

2 Tblspoons Butter (or try Coconut oil if you don’t want butter)

2 Tblspoons Olive Oil

2 Tspoons salt (or to taste)

Freshly ground Black Pepper

2.5 Ltrs Beef Stock (or use vegetable stock if vegetarian)

2 Tblspoons Balsamic Vinegar

3 Tblspoons Brandy (optional)

Splash of Fish Sauce (optional for vegetarians)

Handful dried garlic (optional)

To serve

French Loaf slices about 1.5 cm, lightly toasted

Grated Gruyer Cheese


1Chop onions into quarters and slice (easy in a food processor)

2Melt the butter & oil into the bottom of the slow cooker

3Pile all the onions in with plenty of freshly ground pepper

4Cook on high for about an hour stirring now and then to get the onions all covered by the butter & oil

5Reduce the temp to low and cook for 12+ hours - I have difficulty resisting the temptation to keek peeking, smelling and stirring, and it doesn’t seem to matter!

6The onions should be a rich golden-brown at this point

7Add the stock, vinegar, fish sauce & garlic

8Cook on low for 6-8 hours minimum, the longer you cook it the deeper the flavour

9Add the brandy if using, half an hour or so before serving - add salt now according to taste

10Optional - I like to give the soup a few quick blitzes with my Bamix (wand-style liquidiser), but don’t overdo it, you want the onion slices!

11— To Serve

12Option 1:

13Ladel soup into bowls

14Top the French toasts with grated gruyere cheese; float them on top of the soup and bake or grill (broil if you’re American!) till the cheese bubbles

15Option 2 (if you don’t trust your soup bowls to cope with option 1)

16Top the toasts with gruyere and grill (or broil) till cheese bubbles

17Ladel the soup into bowls and float the cheesy toasts on top

18Enjoy - and wait for the compliments!


1Cooking time is longer than the max 12 hr option, 20 hrs plus

2Preparing the onions is the most time consuming part of this recipe. I cook the onions overnight and then add the stock in the morning to plan to serve that evening.

3The gorgeous fragrance of onions cooking will drift appetisingly around for the duration - blissful,

4Use whatever stock you like - I’ve used home-made stock, tinned consommé (great trick to keep in your storecupboard), and gel or cubed commercial stock - they all work - you could use chicken stock for a lighter soup

5This freezes really well - I freeze the leftovers in portions to take out at random.

Submitted by Bev Horton


6 Reviews

Always lid on for slow cooking (except fudge)

Michelle Giroux

August 24, 2020

In regards to cookig the onions for 12 hrs is the cover on or off?

You can yes 🙂


October 7, 2019

To fasten the cooking time could i put it on high instead?

That’s how I read it 🙂


October 8, 2018

just to clarify the times, you cook the onion on low for 12hrs, then add the stock and cookfor another 6-8 hrs, is that right? thanks

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