WASH AND SALT: When you get your bird home, unwrap and rinse it inside and out with cold water. Pat it dry with paper towels.
Sprinkle it all over with 1 teaspoon kosher salt. The salt makes the meat tender and enhances the flavor (and doesn't make it taste salty). Cover with plastic wrap, and refrigerate until ready to roast (up to 1 day). Bring the bird to room temperature an hour before roasting; then put the fresh rosemary and garlic in the cavity.
Sprinkle chicken with black pepper.
PREHEAT AND ROAST: Preheat oven to 45
On the stovetop, preheat a cast-iron skillet (large enough to hold the chicken) over medium-high heat.
Add olive oil to the pan, and place the bird, breast side up, in the pan. Then place the hot skillet on the middle rack in the oven. (For an easy side, toss new potatoes in a little olive oil and add them to the skil-let after about 20 minutes.) Roast about 1 hour for a 3 1/2-pound bird and up to 90 minutes for a 5-pounder.
TEST FOR DONENESS: After about 50 minutes, use a meat thermometer to check the temperature in the thickest part of the thigh; it should reach 18
Two other quick tests for doneness: Wiggle a chicken leg; if it's loose, it's done. Or cut into the crease where the thigh meets the body; if there are no signs of blood and the juices are clear the bird is done. If it's not done, continue to roast another 10 minutes or so.
Put the chicken on a cutting board with a lip so the juices won't overflow, and let it stand 10 to 15 minutes. Then sprinkle additional black pepper over the top and carve, starting by removing the thighs and legs and then the wings. For the breast, carve from the outside to the inside, in thin even slices.
