Place garlic, anchovies, rosemary and oil in a blender and pulse into a paste.
Pat lamb dry and transfer, fat side up, onto a rack in a roasting pan.
Make several small 1-inch-deep slits in lamb with a paring knife, then rub marinade over entire surface of lamb, pushing some marinade into slits.
Marinate lamb, loosely covered, at room temperature while preheating oven to 200°C.
Sprinkle lamb all over with salt and pepper, then roast until thermometer inserted into thickest part of lamb registers 70°C for medium-rare, 1 1/2 to 1 3/4 hours.
Let stand 30 minutes before slicing.
0 servings