Combine garlic, 1 teaspoon pepper and 1 teaspoon thyme in a small bowl and rub mixture onto the pork.
Place in a large shallow dish; cover and refrigerate for 6 hours or overnight.
Prepare sauce by pouring the port into a medium saucepan and bring to a boil.
Cook about 25 minutes or until reduced to one cup.
Add the cream, shallots, the remaining 1 teaspoon of pepper and 1 teaspoon of thyme and cook over low heat until sauce begins to thicken. Add the cranberries and heat thoroughly. (The sauce can be made up to 24 hours ahead of time and refrigerated, reheat gently.).
Prepare a medium-hot BBQ or preheat the broiler.
Pat the meat dry and rub with oil.
Broil or grill about 15-20 minutes, turning so that all sides are browned.
When meat is done, let stand on a cutting board, loosely covered, for 5-10 minutes.