Microwave the potatoes for 10 mins on
High, turning after 5 mins, and heat oven to
220C/fan 200C/gas 7. Meanwhile, heat the
oil in a frying pan, then fry the mushrooms
over a high heat until golden. Stir in the
cornflour, gradually add 100ml milk, then
simmer to a smooth sauce. Season to taste,
then stir in the chicken and parsley.