French Onion Soup Gratiné is one of the great classics of French cuisine — deeply rich, intensely flavoured onion broth topped with crusty bread soaked in the soup and covered with a golden, bubbling blanket of melted Gruyère. It’s soul-warming, gloriously indulgent and easier to make than you might think.
Ingredients (serves 4)
- 1 kg onions, thinly sliced
- 50 g butter
- 1 tbsp olive oil
- 1 tsp sugar
- 2 garlic cloves, crushed
- 200 ml dry white wine (or dry cider)
- 1 litre good beef stock (or vegetable stock)
- 1 bay leaf, 2 sprigs of thyme
- Salt and pepper
- 8 thick slices of baguette, toasted
- 200 g Gruyère (or Comté), grated
Instructions
- Melt the butter and olive oil in a large pot over medium-low heat. Add the onions and sugar. Cook, stirring occasionally, for 40–50 minutes until deeply golden and caramelised. This step cannot be rushed — it’s where all the flavour comes from.
- Add the garlic and cook for 2 minutes. Pour in the white wine and let it bubble and reduce for 3 minutes.
- Add the stock, bay leaf and thyme. Season. Simmer for 20 minutes.
- Preheat the grill to high. Ladle the soup into individual ovenproof bowls.
- Float 2 baguette slices on top of each bowl. Cover generously with grated Gruyère.
- Place under the grill for 3–5 minutes until the cheese is bubbly and gloriously golden.
- Serve immediately — carefully, as the bowls will be very hot!
Bon appétit! 🧅🧀🇫🇷