French onion soup is a classic dish found in most French cafes known as Soupe à l’Oignon Gratinée. Translated as grilled onion soup. A mainstay dish in France, which is also very popular in Belgium. The distinct smell of onions, garlic and cheese do an easy job to increase your appetite for this soup. Just like onions have many layers, so does onion soup in flavours and textures:

 1. The rich beef stock: it is essential to have a good stock to make this soup shine above the rest. Homemade beef stock is traditionally used. In my blog “Why stock making is a must”, I explain the importance of stock-making for most of my dishes, mainly because it is so healthy and adds so much flavour and depth to the dish. If you prefer to use chicken stock or vegetable stock, these work fine but may lack that boldness that beef has. TIP: Freeze portions of homemade stock for future soup making session.

2. The onions: The star of the show! Using yellow or brown onions are important as the amount of sugar released from these varieties are perfect for the gentle, slow frying that gives them the perfect caramelisation. This slow caramelisation, in turn, sweetens and flavours the soup enormously. If possible, try to buy organic onions for the best flavour and health benefits.

3. The strong cheese: The Swiss make one of the strongest and most expensive cheese in the world: Gruyère. This cheese goes classically with onion soup for its rich flavour and excellent gooey and melting ability. Other good cheeses to use are Emmental, Jarlsberg and Fontina mixed with a little Parmesan. Failing all the above, a strong Cheddar will do the trick. Just don’t use soft cheeses like mozzarella or feta. These will slip off the bread and drown in the soup.

4.The baguette: Here’s where most of us struggle to find a gluten-free onion soup in most restaurants due to the gluten baguette toast served. Making this at home, I use store-bought or homemade baguette slices to add to the soup after rubbing each piece with a garlic clove, toasting it slightly and finally popping it on top of the soup with a generous serving of grated strong cheese. TIP: Freeze leftover slices of baguette to have handy to serve with this soup.


  • 5 large brown or yellow onions, thinly sliced (organic, if possible)
  • 2 tablespoons butter
  • 2 tablespoons olive oil
  • 3 garlic cloves, finely chopped
  • 2 teaspoons brown sugar
  • 1 tsp fresh thyme or ½ tsp dried thyme leaves
  • 2 tablespoons cornflour
  • 200ml dry white wine
  • 1 ½ litres store-bought or homemade beef stock
  • 1 store-bought or homemade gluten-free baguette bread, sliced
  • 100g strong cheese, grated (Gruyère, Emmental, Jarlsberg)
  • Extra 2 garlic clove, to rub bread and inside of soup bowls

Salt and freshly cracked black pepper, to season


  • Large casserole stove pot with lid
  • Heatproof soup bowls

Step-by-Step Instructions

  1. Melt 1 tablespoon of butter with 1 tablespoon of oil in a large casserole stove pot on medium-low heat. The butter should melt gently. Lower the heat even more if it melts too fast and sizzles.

2. Add the thinly sliced onions and allow to cook down, stirring occasionally for 20 minutes. Add the extra tablespoon of butter and oil when the onions seem on the dry side.

3. Once the onions appear soft and slightly brown, add the garlic, sugar and thyme leaves and cook for a further 20 minutes until the onions appear (and smell!) caramelised. They should have a nice rich brown colour. Keep an eye on the onions and stir often to avoid burning the onions and garlic.

4. Sprinkle the cornflour over the onions and stir in well for 2 minutes, scraping the bottom of the pot to remove any residue.

5. Add the wine and enjoy the aroma as it deglazes the pan and mixes in with the onions.

6. Add the beef stock and slowly bring to the boil, then reduce the heat to a low simmer and keep it low and slow for 45 minutes with the lid on.

7. Cut the baguette bread into 5cm thick slices and rub a peeled garlic clove over both sides of the bread. Set aside.

8. Rub the other garlic clove in the inside of each heatproof soup bowl.

9. Grate the strong cheese and set it aside.

10. Preheat the grill/broiler to medium heat.

11. Gently toast the baguette slices on both sides. Remove and set it aside.

12. Pour the onion soup evenly into each soup bowl. Place the toasted baguette slice on top of the soup and sprinkle generously with the strong cheese.

13. Grill the soup bowls for 10 minutes or until the cheese has melted and slightly golden and bubbly, and Voila! You have made a perfect Soupe à l’Oignon Gratinée!!

  • Makes 8 to 10 medium soup bowls
  • Freezes well (without the baguette and cheese)
  • Keeps for 3 to 4 days in the fridge

If you would like the onion soup to be thicker, add extra cornflour and cook with the lid off. Adding a whole peeled potato to the soup also thickens it slightly. Remove the potato before serving.


Plan ahead and make a freshly made gluten-free baguette to go with this French onion soup.