This "split" roast chicken, formally called a spatchcock chicken, roasts faster than a traditionally roasted chicken. That's because it's split open by easily removing the back and flattening out the chicken.
Turn the chicken over on to its breast side. Cut the chicken along both sides of the backbone with strong kitchen scissors. Remove the backbone and discard it.
Rinse the chicken and pat it dry. Lay it flat on a cutting board, breast side up. With both hands, push on the breast bone to flatten the chicken as much is possible. Remove the wingtips.
Choose your preferred rub (the herb rub is above and the garlic rub below) and mix it with the 1/4 cup of olive oil. Rub the mixture into the top of the skin as well as under the skin, then brush the top of the chicken with a bit more olive oil.
Place the coated chicken in a shallow roasting pan, skin side up. Cover and set aside in the refrigerator for one hour for the flavors to meld.
Preheat the oven to 450°F.
Take the chicken out of the refrigerator. Bake the chicken, uncovered, on the lowest rack of the oven for 45 to 55 minutes, until there is no pink near the bones.