So simple, so perfect, this is a recipe that can make the world seem alright again. It originated as a hearty soup for Paris market workers who needed to warm themselves up on cold mornings. France Vidal loves it as her winter treat.






Skill level

Average: 3.1 (193 votes)

She prefers not to use stock as the basis, using water instead. She advises to buy the best brown onions, fresh with papery skins, and to cook them until deeply golden, as that’s where all the depth of flavour and sweetness come from. She also says to use the best gruyère and baguette.


  • 60 g unsalted butter
  • 4–5 onions, finely sliced
  • 50 g plain flour 
  • 2 litres water 
  • 200 ml white wine
  • sea salt and freshly ground black pepper
  • 100 g gruyère, ½ cut into cubes and ½ grated
  • 1 baguette

Cook's notes

Oven temperatures are for conventional; if using fan-forced (convection), reduce the temperature by 20˚C. | We use Australian tablespoons and cups: 1 teaspoon equals 5 ml; 1 tablespoon equals 20 ml; 1 cup equals 250 ml. | All herbs are fresh (unless specified) and cups are lightly packed. | All vegetables are medium size and peeled, unless specified. | All eggs are 55-60 g, unless specified.


Melt the butter in a heavy-based saucepan and add the onion. Sauté for 25 minutes, stirring from time to time, until a deep golden brown. 

Add the flour and stir for 2 minutes, then add the water and wine and season with salt and pepper. Stir in the cubes of cheese and bring to the boil, then reduce the heat, cover with a lid and simmer for 20–25 minutes. Check the seasoning.

Slice the baguette and sprinkle the slices with the grated cheese. Grill until the cheese melts.

Ladle the soup into bowls and serve with slices of grilled cheese baguette on top.