BEFORE YOU START: An optional step for crisper skin is to pat the chicken dry, sprinkle with the seasonings, as directed below, and then place the chicken on a baking rack that has been set over a baking dish or rimmed baking sheet. Then refrigerate, uncovered, for at least 4 hours or, ideally, overnight. This "dry brine" technique will give the seasoning time to permeate the chicken and help dry out the skin. Dry skin equals crispier skin, plus the process enables the chicken to retain more of its natural moisture when cooked.
Prepare the chicken: Remove the pack of giblets from the chicken. Save for use in homemade stock, if desired. Pat the chicken dry, and place it in a roasting pan. (I often use a 9×13 Pyrex baking dish; you may set the chicken on a rack, but this is not mandatory. The increased airflow will create crisper skin on the bottom, especially if you followed the dry brine step above.) Place the onion and lemon halves in the cavity of the chicken and sprinkle salt, pepper, and thyme all over the inside and outside. (Helpful seasoning hint: I use ½ teaspoon salt, and about ¼ teaspoon each black pepper and dried thyme per pound of chicken. So for a 6-pound chicken, I use 1 tablespoon salt and 1½ teaspoons each pepper and thyme.)
Preheat the oven to 275℉ and roast: Let the chicken sit at room temperature while the oven is preheating or for up to an hour before cooking. Roast, uncovered, for 3-4 hours. If the chicken is smaller, cook on the low end of the time frame and vice-versa. But really, if you keep the chicken in a half hour longer than intended, it will still taste great. I’ve done this!
Let the chicken rest for 10-15 minutes before carving.
Notes
*Larger or smaller chicken? I've cooked an 8-pound “oven stuffer roaster” and it was done within the stated timespan as well. A smaller chicken will likely come to temperature before 3 hours but will not dry out when kept in the oven longer. If you wish to remove from the oven early, simply check with a meat thermometer. The thickest part of the thigh should read 180℉.Optional extras: You may also add half a head of garlic and a few sprigs of fresh thyme to the chicken cavity prior to cooking. Feel free to mix up the herbs, as well, using dried Italian seasoning, dried or fresh rosemary, oregano, marjoram, chives, etc.More on crispy skin: Without the optional dry brine step, slow roasting prioritizes tender, juicy meat over fully crisped skin. You can broil briefly at the end to add an extra hint of golden crispiness to the top, if desired. And read on...Convection option: If your oven has a convection option, using it will cook the chicken about 25% faster and increase the overall crispness of the skin.Meal prep and storage: Leftovers are perfect served cold, reheated, or in any recipe that calls for the addition of cooked chicken. Additionally, two chickens can easily be baked at the same time. The cooked meat will keep for up to a week in the refrigerator and freezes well. Lastly, a whole chicken makes a convenient and welcome meal when you wish to prepare dinner for a friend.