Place tenderloin in a 13- x 9- x 2-inch baking dish; set aside.
Combine remaining ingredients, except parsley, in a small saucepan; bring to a boil. Pour over tenderloin; cover and marinate overnight in refrigerator.
Place tenderloin on a rack in a shallow roasting pan, reserving marinade. Tuck narrow end under to make roast more uniformly thick. Insert meat thermometer, if desired.
Bake, uncovered, at 450° for 40 minutes or until meat thermometer registers 140° (rare); baste with marinade.
Cut tenderloin into 1-inch slices. Arrange on a warm serving platter. Garnish with parsley, if desired.