I love this cozy luxurious French Onion Soup.
Slow-cooked caramelized onions, simmered with rich beef stock and topped with melted-Gruyere-toast croutons.
The onions mellow and gain a rich sweetness as they cook down - adding so much flavour to this glorious soup.
I've waited far too long to put this recipe on the blog!
I was waiting for Chris to sharpen the knives so I could slice up the SIX onions that go into this soup.
It might sound like a lot for a recipe that serves four people, but they cook down and mellow beautifully, so they're a little sweet with tiny bit of a nutty undertone.
You want to get a really good caramelisation going for maximum flavour, so those onions need to be cooked low and slow in plenty of butter.
- I use about 6 tablespoons of butter (plus a splash of oil) and cook the onions for about 45-55 minutes until they're lovely and golden.
- We then add a little garlic and some white wine for depth of flavour.
- Bubble the wine until it's nearly all evapourated, then we stir in flour - which helps to thicken the soup slightly.
- Next in goes plenty of good quality beef stock and a splash of Worcestershire sauce.
- Everything is simmered for a further 30 minutes, before the soup is ladled into bowls and topped with gooey Gruyere cheese croutons.
Check out the recipe card at the bottom of this post for full ingredients and instructions.
👩🍳PRO TIP Be sure to stir the onions regularly so they don't 'catch' on the bottom of the pan when you're cooking them.
🍽️ Soup Bowls
I love to serve this soup in classic white French Onion Soup bowls. I bought these soup bowls (<-- affiliate link) from Amazon.
Be sure to check that your soup bowls are grill-proof (broiler-proof in the USA) if you're intending to melt the cheese directly in the bowls.
If you're wondering whether I cried when chopping so many onions, the answer is no!
I wear contact lenses which makes me immune to the effects of all but the very strongest onions!
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French Onion Soup
- 90 g (6tbsp) unsalted butter
- 1 tbsp oil
- 6 medium yellow/brown onions - about 1.2kg/2.6lbs, peeled, halved and thinly sliced
- ½ tsp salt
- 1 tsp black pepper
- 3 cloves minced garlic
- 180 ml (¾ cup) white wine
- 2 tbsp plain (all-purpose) flour
- 1.5 litres (a splash over 6 cups) good quality strong beef stock - *See note
- 1 tbsp Worcestershire sauce
Cheese Crouton Topping:
- 1 small baguette sliced into 2cm (¾ inch) slices - (we need 8 slices)
- 100 g (1 packed cup) grated Gruyere cheese
- fresh thyme leaves for garnish
- Add the butter and oil to a large Dutch oven or heavy-based saucepan. Heat over a medium-to-low heat.90 g (6tbsp) unsalted butter, 1 tbsp oil
- When the butter has just melted, add the sliced onions, salt and pepper.6 medium yellow/brown onions, ½ tsp salt, 1 tsp black pepper
- Cook, uncovered, for about 45-50 minutes, stirring occasionally at first, then often in the last 15-20 minutes (to stop the onions 'catching' on the bottom of the pan), until the onions are golden brown and caramelised. Be sure to keep a close eye on the onions, especially in the last 20 minutes, as you don't want them to burn at all. Turn down the heat a little if you're worried they'll burn.
- Add the garlic and cook for one minute, whilst stirring.3 cloves minced garlic
- Add the wine to 'deglaze' the pan and pick up all of those flavourful bits. Turn up the heat to medium-high and cook for about 5-8 minutes, stirring often until almost all of the liquid has evaporated and you can no longer smell the wine.180 ml (¾ cup) white wine
- Turn the heat back down to medium and stir in the flour. Cook for one minute, stirring constantly.2 tbsp plain (all-purpose) flour
- Add the stock and Worcestershire sauce. Stir together, turn up the heat and bring to the boil.1.5 litres (a splash over 6 cups) good quality strong beef stock, 1 tbsp Worcestershire sauce
- Turn the heat down to a simmer, stir again and place a lid on the pan. Simmer for 30 minutes. After 30 minutes, taste and add a little more slat if required (this wil depend on the saltiness of your stock).
- When the soup is nearly ready, start on the cheese baguette slices/croutons.
Method 1 - Melting the cheese directly in the bowls
- Once the soup is ready, ladle out into grill(broiler)-safe bowls.
- Top each bowl with two of the baguette slices. Divide the grated Gruyere between the bowls, sprinkling it all over the soup and bread.1 small baguette sliced into 2cm (¾ inch) slices, 100 g (1 packed cup) grated Gruyere cheese
- Place the bowls on a tray under the grill (broiler) and slide under the heat.
- Grill for 2-4 minutes, until the cheese is melted and bubbling.
- Carefully remove the bowls (they'll be VERY hot) and serve sprinkled with fresh thyme leaves.fresh thyme leaves for garnish
Method 2 - Melting cheese on the crouton separately
- Toast the baguette slices on both sides under the grill (broiler) until lightly browned.1 small baguette sliced into 2cm (¾ inch) slices
- Once the baguette slices have been lightly browned under the grill (broiler), sprinkle them with the Gruyere and place back under the grill.100 g (1 packed cup) grated Gruyere cheese
- Toast until the cheese is melted and bubbling.
- Ladle the soup out into bowls and place two slices of the cheese toasts on top of each bowl.
- Sprinkle with fresh thyme leaves and serve.fresh thyme leaves for garnish
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