Mix together the onion powder, garlic powder, oregano, smoked paprika, basil, thyme, black pepper, and cayenne. Store in an airtight container.
Seasoning the chicken [1 to 3 days before serving; for a chicken closer to 4 pounds, at least 2 days]:
Remove and discard the lump of fat inside the chicken. Rinse the chicken and pat very dry inside and out. Be thorough—a wet chicken will spend too much time steaming before it begins to turn golden brown.
Season the chicken liberally all over with salt and the spice mix (approximately 3/4 teaspoon sea salt per pound of chicken). Season the thick sections a little more heavily than the skinny ankles and wings. Sprinkle a little of the salt just inside the cavity, on the backbone, but don’t otherwise worry about seasoning the inside. Twist and tuck the wing tips behind the shoulders. Cover loosely and refrigerate.
Roasting the chicken:
Preheat the oven to 475°. [Depending on the size, efficiency, and accuracy of your oven, and the size of your bird, you may need to adjust the heat to as high as 500° or as low as 450° during the course of roasting the chicken to get it to brown properly. If that proves to be the case, begin at that temperature the next time you roast a chicken.]
Choose a shallow flameproof roasting pan or dish barely larger than the chicken, or use a 10-inch skillet with an all-metal handle. Preheat the pan over medium heat. Wipe the chicken dry and set it breast side up in the pan. It should sizzle.
Place it in the center of the oven and listen and watch for it to start sizzling and browning within 20 minutes. If it doesn’t, raise the temperature progressively until it does. The skin should blister, but if the chicken begins to char, or the fat is smoking, reduce the temperature by 25 degrees. After about 30 minutes, turn the bird over [drying the bird and preheating the pan should keep the skin from sticking]. Roast for another 10 to 20 minutes, depending on size, then flip back over to recrisp the breast skin, another 5 to 10 minutes. Total oven time will be 45 minutes to an hour.
Finishing and serving the chicken:
Remove the chicken from the oven and turn off the heat. Lift the chicken from the roasting pan and set it on a plate. Carefully pour the clear fat from the roasting pan, leaving the lean drippings behind. Slash the stretched skin between the thighs and breasts of the chicken, then tilt the bird and plate over the roasting pan to drain the juice into the drippings. Set the chicken in a warm spot, and leave it to rest for a bit—the meat will become more tender and uniformly succulent as it cools. Cut the chicken into pieces and serve.