Using sharp knife, remove thin membrane from lamb. Cut tiny slits all over lamb; insert garlic slivers and bacon. Brush oil over lamb. Sprinkle with rosemary, salt and pepper.

Roast on rack in roasting pan in 325°F (160°C) oven for 1 hour and 40 minutes to 2 hours or until meat thermometer registers 145°F (63°C) for medium-rare or 160°F (71°C) for medium. Remove to cutting board; tent with foil and let stand for 15 minutes.

Skim fat from pan drippings. Add 1/2 cup (125 mL) water to pan; bring to boil, scraping up brown bits. Strain and keep warm.

Place lamb with meatier portion facing up. Grip shank end firmly with towel. Cutting down to bone, cut 1/4-inch (5 mm) thick slices. With knife parallel to bone, cut slices from bone. Turn lamb so remaining meaty portion faces up. Carve as for first side. Arrange on platter; pour pan juices over top.