By Guy Watson
The secret of this recipe lies in cooking the leeks long and slow, so that they become sweetly caramelised. The rest takes no time at all and you can exercise your imagination adding extra toppings.
Heat the oven to 200°C/Gas 6.
Heat the oil or butter in a heavy-bottomed saucepan and add the leeks and thyme. Slow-fry the leeks as described until they are very soft and starting to brown, a good 10–15 minutes. Cover the pan initially to h