Ingredients
- 55 g (2 oz) butter
- 1 tablespoon olive oil
- 1 kg (2 lb 4 oz) onions, thinly sliced into rings
- 840 ml (28 fl oz) vegetable stock
- 125 ml (4 fl oz/1/2 cup) dry sherry
- 1/2 baguette
- 35 g (1 oz/ 1/3 cup) grated parmesan cheese
- 125 g (4 1/2 oz/1 cup) finely grated cheddar or gruyere cheeses
- chopped parsley, to serve
Method
1. Heat the butter and oil in a large saucepan, then add the onion and cook, stirring frequently, over low heat for 45 minutes, or until softened and golden brown. It is important not to rush this stage—cook the onion thoroughly so that it caramelises and the flavours develop.
2. Add the vegetable stock, sherry and 250 ml (9 fl oz/1 cup) water. Bring to the boil, then reduce the heat and simmer for 30 minutes. Season to taste.
3. Meanwhile, slice the bread into four thick slices and arrange them in a single layer under a hot grill (broiler). Toast one side, turn and sprinkle with parmesan, and toast until crisp and golden and the cheese has melted.
4. Put the bread slices into serving bowls. Ladle in the hot soup, sprinkle with the cheese and parsley and serve.
