Place the pork tenderloin on a rack in a roasting pan. (If you don’t have a roasting pan, a cooling rack set inside a cookie sheet works well). If using freshherbs they should be finely chopped. Combine oil, salt, rosemary and thyme in a small bowl.
Using your fingers, massage the mixture into the pork tenderloin covering all sides.
Roast the pork for 15 minutes and then reduce the heat to 425 degrees F and roast for additional 30 minutes. Pork is done when an instant-read thermometer shows an internal temperature of 155 degrees F.
Remove the roast from the oven and allow to rest for 15-20 minutes before carving.