Use vegetable, not chicken, stock for a vegetarian dish.
250g/9ozleeks, white and pale green parts only
1litre/1¾ptstrong vegetable or chicken stock
100g/3½ozFontina cheese, grated
6slicesFrench stick, toasted
salt and freshly ground white pepper
Cut the leeks into rings and wash thoroughly. Dice the potatoes. Sweat the leeks in 3tablespoons of olive oil, add the potato and stir into the leeks for a few minutes. Add the stock and milk. Season and gently simmer for 45 minutes, or until potatoes are cooked. Transfer the soup to a liquidizer, add the cream and liquidize for 1 minute. Return the soup to the heat, bring to just under boiling point. Divide the soup between 6 deep soup bowls, put toasted bread on top and cover with cheese. Pass lightly under a hot grill. Shave white truffle on top.