About 20 minutes before cooking, remove the chicken from the fridge and drain off the marinade and discard. The meat needs to be at room temperature to cook evenly. Cook the butterflied breasts over direct heat on one side for 3 minutes, then flip over and cook for another 3 minutes. Then cook for another 3 minutes on each side. Check the chicken is cooked through by making a small cut into the thickest part of one – there should be no pink showing.