In a mixing bowl, combine olive oil, rosemary, thyme, garlic, salt, and pepper.
Rub the herb mixture all over the sirloin tip roast.
Place the roast in a roasting pan.
Roast in the preheated oven for 15 minutes, then reduce the temperature to 325°F (165°C) and continue roasting for about 75 minutes, or until the internal temperature reaches 135°F (57°C) for medium-rare.
Remove from the oven and let the roast rest for 15 minutes before slicing.