I must admit, it was nice looking at a colourful plate again! We used half a chicken - just under one kilo in weight and cooked ours for 40 minutes in a hot oven (fan at 180 degrees). Our thermometer told us it was cooked - and we tend to use this now as a guide as chicken can dry out if overcooked.
We heated up a baking tray and placed the half chicken carcass side down (flatten chicken first). It's not covered with foil, which helps crisp up the skin nicely.