Heat the oil in a heavy based frying pan, fry the leek and mushrooms for 2 minutes. Add the rice to the pan and cook for 1-2 minutes. Gradually add the stock and bring to the boil. Simmer for 20 minutes. Blanch the vegetables, then add to the risotto with the chicken and season to taste. Serve immediately. NOTES : A quick and simple supper dish.Ideal served hot or cold.