French Onion Soup (Soupe à l'Oignon)

Ingredients

• 50g unsalted butter
• 1 tbsp olive oil
• 1kg onions (about 6 large), halved and thinly sliced
• 1 tsp caster sugar
• 1 tsp fine sea salt
• 2 cloves garlic, crushed
• 1 tbsp plain flour
• 150ml dry white wine
• 1.2 litres good beef stock
• 3 sprigs fresh thyme
• 2 bay leaves
• 8 thin slices baguette, toasted
• 150g Gruyère, coarsely grated
• Freshly ground black pepper

Method

1. Melt the butter with the oil in a large heavy-based pan over a medium heat. Add the onions, sugar and salt, then cover and cook for 15 minutes, stirring now and then, until soft and translucent.

2. Remove the lid, lower the heat slightly and cook for a further 40 minutes, stirring often, until the onions are a deep, even golden brown. Do not rush this step, as it builds the flavour of the soup.

3. Stir in the garlic and flour and cook for 1 minute. Pour in the wine and let it bubble until almost completely reduced, scraping up any caramelised bits from the base of the pan.

4. Add the stock, thyme and bay leaves. Bring to the boil, then simmer gently, uncovered, for 20 minutes. Remove the thyme and bay leaves, then season with pepper and more salt if needed.

5. Heat the grill to high. Ladle the soup into four ovenproof bowls and set them on a baking tray. Float two slices of toasted baguette in each bowl and pile the Gruyère on top.

6. Grill for 3 to 5 minutes until the cheese is melted, bubbling and flecked with brown. Let the bowls stand for 2 minutes before serving as they will be very hot.