- 150 g butter
- 1.8 kg mixed onions, finely sliced
- sea salt and freshly ground black pepper, to taste
- 1/2 cup dry sherry
- 6 sprigs thyme
- 1 bay leaf
- 2 litres good chicken stock
- 1 t fish sauce
- 1 t apple cider vinegar
- 6 slices ciabatta, toasted until crisp
- 2 garlic cloves
- 200 - 250 g mature Cheddar, grated
- chives, finely chopped, to garnish
1. Melt the butter in a large saucepan. Add the onions and cook, while stirring, over a medium to high heat for about 10 minutes. Reduce the heat to medium-low and, stirring often, cook the onions for 11⁄2–2 hours. You may need to add 1 T water at the end if the onions start to burn. Once they are perfectly caramelised, season.
2. Add the sherry and simmer until all the alcohol has evaporated, about 5 minutes, then add the thyme, bay leaf and chicken stock and simmer for 30 minutes over a medium heat.
3. Add the fish sauce and the apple cider vinegar, season and remove the thyme stalks and the bay leaf.
4. Turn the oven onto grill and divide the onion soup between 6 medium-sized ovenproof bowls, leaving enough aside for another ladle of soup for each bowl.
5. Place the toast in the soup and generously sprinkle over the cheese, then add the last ladle of soup to each bowl. Sprinkle with more cheese and place under the grill for about 10 minutes, or until the cheese is bubbling. Remove from the oven and eat while hot but not a health hazard.