Put broccoli in bottom of roasting tin then put chicken on top
Cover with loads of chopped mushrooms
Mix the soup, cream and mayonnaise in a bowl, then pour over the chicken and broccoli. Most of the mixture should sink through the gaps into the stuff below.
Cover with a layer of grated cheese
Cover with a layer of breadcrumbs
Bake in oven until cheese melts and is bubbling away nicely