Combine the salt, garlic, thyme, ginger, and pepper; rub over entire roast.
Place roast with fat side up on a rack in a shallow roasting pan.
Bake, uncovered, at 350 degrees for 2 hours.
Meanwhile, in a saucepan, combine brown sugar and cornstarch.
Stir in the remaining glaze ingredients until smooth.
Bring to a boil; cook and stir for 2 minutes.
Brush some of the glaze over the roast.
Bake 1 hour longer or until a meat thermometer reads 160 degrees, brushing occasionally with glaze.
Let stand for 10 minutes before slicing; serve with remaining glaze.