Place roast, fat-side down, on microwave roasting rack in 11 x 7-inch microproof baking dish.
Insert temperature probe horizon-tally into thickest part of roast without touching fat.
Place in oven.
Cover roast lightly with waxed paper.
Plug in probe.
Cook on 70 with temperature probe set at 90°F.
At signal, turn roast over, being careful not to remove temperature probe.
Cover and cook on 70 with temperature probe set at 145°F.
Cover roast with aluminum foil and let stand 10 minutes.
During standing time, internal temperature of roast will rise to 160°F.