I've bought an expensive 3.5Kg free range chicken to have on Christmas day. It will be wrapped in foil to rest for about 45 mins while the roast potatoes are cooking in the oven. Should I reduce the overall cooking time of the chicken by 5 or 10 mins? I'd imagine it will continue to cook while wrapped in the foil and dish towels and I don't want to spoil it by overcooking it. I don't have a thermometer and usually just go by times. Help! How would you cook it?