In Dinner, Gluten Free, Lunch, Nut Free, Recipes, Uncategorized, Vegetarian

Red Onion Soup

Red Onion Soup

This easy French Onion soup recipe brings back wonderful memories of my favourite eatery in Paris. By using red onions, you don’t need to spend hours perfecting the caramelization and my secret weapon is using balsamic to give the onions colour. This soup is delicious as it is, although adding a considerable amount of cheese takes it to another level!
Prep Time 20 minutes
Cook Time 50 minutes
Servings 6 serves


  • 7-8 red onions, sliced (1.5kg)
  • 2 garlic cloves, finely chopped
  • 2 tbsp. olive oil light and mild (or your preference of oil)
  • 2 ¼ pints boiling water
  • 2 tbsp. balsamic (I recommend the brand Belazu)
  • 2 tbsp. arrowroot or corn flour
  • 3 tbsp. honey or agave
  • 1 vegetable, chicken or beef stock cube or 1 dessertspoon of herbamare
  • sea salt
  • white pepper

Serving suggestion

  • baguette, or bread of your choice
  • honey mustard
  • Gruyère cheese (or substitute Comté, Emmental, mozzarella, young Manchego, or another melting cheese), plus parmesan cheese


  • In a large saucepan add the oil together with the sliced onions, and sauté over a gentle heat until soft for 10 minutes. Season with sea salt and a touch of white pepper. Add the chopped garlic and ¼ pint of boiling water, cook covered over a medium heat for 20 minutes,stirring occasionally.
  • Reduce the heat to simmer, add the balsamic, and stir into the onions, then add the arrowroot or corn flour, keep stirring to ensure there’s no lumps in the flour and its fully dissolved (you can add a touch of water to the flour in a small bowl to dilute the flour, then add to the onions). Turn up the heat and add your choice of stock cube or hedrbamare with 2 pints of boiling water. Add the honey, stir the soup and then check for seasonings, then bring to the boil, cover and simmer for 20 minutes.
  • Leave the soup for a couple of hours before serving for the flavour to deepen. You can make the soup the day before serving as the flavour improves.
  • For the cheese croutons, thickly slice the baguette or your choice of bread, brush both sides with olive oil, scatter them on baking tray and bake until the bread dries out and the edges are golden brown.
  • Then scrape lightly on one side with Dijon mustard and then sprinkle some Gruyère over each slice of bread and place in the pre-heated grill until the cheese bubbles and browns, (keep an eye on them so they don’t burn).
  • When ready to serve, heat the soup in the saucepan, then place a handful of grated cheese at the bottom of each oven proof serving bowl, fill the soup bowl with the onion soup, leaving space for the croutons on top. Once you’ve added the crouton around the edge add some grated cheese of your choice and a handful of grated parmesan cheese, then you’re ready to place back under the grill.
  • Place the soup bowls on a pre lined baking tray with foil (as it will bubble over) and put under the grill, keep an eye on this stage as you don’t want the croutons or cheese to burn.
  • If you would rather skip this stage, you can alternatively, just heat the soup, serve in individual bowls, again you can put a handful of cheese in each bowl at the bottom before pouring in the soup and serve the toasted cheese croutons on the side, (some people prefer the toast not to be soggy) plus it’s less stressful! It’s entirely up to you how you like to serve it - whichever way it’s going to be delicious.
  • Enjoy!
  • If you make this recipe, I’d LOVE to see how you get on so please either send me a photo to or post a picture to Instagram using the #myrelationshipwithfood and tag@myrelationshipwithfood


LISA’S TIP – French onion soup is traditionally a meat broth-based soup with notoriously famous crouton with melting cheese on top. A couple of suggestions, I use herbamare as my choice of stock, so that my vegetarian guests can enjoy. And the amount of cheese you add to the soup is a matter of preference, I love nothing more than cheese melting in the soup and at the bottom. And I personally prefer to serve a large platter to melted cheese croutons on the side, and then my guests can eat them at their leisure or place them in the soup if they prefer.
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