If you'd like to roast a whole breast instead of half, you can use the same method of browning it in a very hot oven, then loosely covering it with foil and continuing to roast until done. But you'll need more time. The last time I cooked a whole, 3 1/2 lb. breast, I baked it for 1.5 hours. It took that long for an instant-read thermometer to register 160 degrees F. It turned out fabulous, with crispy, savory skin and very juicy meat, the juiciest we’ve ever had actually. But it does require a longer time commitment than using breast halves.