Ingredients:

• 5-6 large onions, thinly sliced

• 3 tablespoons unsalted butter
• 1 tablespoon olive oil
• 2 tablespoons all-purpose flour
• 6 cups beef broth
• 1/2 cup red wine (optional)
• 1 bay leaf
• 2 sprigs of thyme
• Salt and pepper, to taste
• French baguette, sliced
• Gruyere cheese, grated

Instructions:

1. In a large soup pot, melt the butter and olive oil over medium heat.
2. Add the sliced onions and cook for about 30-40 minutes, stirring occasionally, until the onions are caramelised and golden brown.
3. Add the flour and stir to coat the onions. Cook for an additional 2-3 minutes.
4. Add the beef broth, red wine (if using), bay leaf, thyme, salt, and pepper. Stir to combine.
5. Bring the soup to a simmer and let it cook for about 20-30 minutes to allow the flavours to meld together.
6. Preheat the oven to 200°C.
7. Toast the sliced baguette in the oven until crispy.
8. Ladle the soup into oven-safe bowls and place the toasted bread on top of the soup.
9. Sprinkle the grated Gruyere cheese on top of the bread.
10. Broil the soup bowls in the oven for a few minutes, or until the cheese is melted and bubbly.