Place pork loin roast in an ovenproof dish and bake for 1 hour and 15 minutes or until temperature of a thermometer inserted into center of meat reaches 63 °C (145 °F).
Remove roast from oven and cover with aluminum foil. Let stand for 10 minutes before slicing.
Barbecue
Preheat barbecue to high heat, i.e., about 290 °C (550 °F).
Sear pork loin roast on all sides.
Turn off one burner and place meat on that side.
Cook pork over indirect heat, turning several times, for 45 minutes to 1 hour or until temperature of a thermometer inserted into center of meat reaches 63 °C (145 °F).
Remove from barbecue and cover with aluminum foil. Let stand for 10 minutes before slicing.
