Preheat oven or grill to 275 degrees F. (Note: If cooking pork tenderloin in oven, use roasting pan with rack.)

Rub olive oil on tenderloin. Season with salt, pepper and dried herbs. Let sit 30 minutes.

In mixing bowl, combine butter and balsamic vinegar glaze, mixing well.

Place tenderloin on grill or in oven for 20 minutes, then brush tenderloin with glaze-butter sauce.

Flip tenderloin every 5 minutes and brush with sauce.

Using meat thermometer, check tenderloin in thickest portion. Tenderloin is done at 142 degrees F.

Rest 20 minutes.

Slice and serve with your favorite sides.