Please, please do not use any form of plastic whether cling film or plastic tubs for re-heating food or drinks. When plastic is heated it gives off 'dioxins' which are a cancer causing agent. Someone I know has recently died (37yrs) from stomach cancer, he lived off microwave meals. The hospital said it was probably due to re-heating plastics over a long period.
For cooking chickens in the oven, rub a little butter on the skin, wrap in tin foil and place inside a roasting tin. Do not roast open as this will dry out the meat. If you boil chicken you will loose all the flavour of the chicken in the water, hence the meat will taste bland.