1kg brown onions, thinly sliced
3 tablespoons dry sherry
1.2 liters beef stock
2 tablespoons thyme, picked leaves
For the croutons:
1 baguette, sliced
Extra-virgin olive oil
1 garlic clove, halved
100g Gruyère, grated
Cook the soup.
Heat the butter in a large frying pan and gently cook the onions and thyme for 20 minutes until the onions are soft. Increase the heat and cook the onions for another 15 minutes stirring occasionally until they caramelize. Add the sherry and simmer for 2 – 3 minutes then add the stock and bring the mixture to the boil. Season with salt and pepper, reduce the heat and simmer for 10 minutes.
Make the croutons.
Rub each slide of the bread slices with garlic and drizzle with a little of the oil and toast the bread. Sprinkle with cheese and place under the grill until the cheese is golden and bubbly.
Serve the soup with the cheese croutons on top.