Stuff cavity with herbs and garlic cloves. Season skin with salt and immediately set roaster in pan and set in oven. Meanwhile, scrub potatoes clean, leave skin on and cut, lengthwise into quarters so you have long potato wedges. Return bird and potatoes to oven and roast for an hour more. Strain out juices and discard fat.
Return juices to roasting pan.
Scoop herbs and garlic out of bird cavity and add to roasting pan. Reduce juices by half. Season with salt and pepper. With slotted spoon, remove herbs and garlic. Right before serving whisk in butter and parsley.