Place roast on rack in small roasting pan. Combine garlic, ginger, oil, mint, pepper and salt; spread all over roast. Pour 1 cup (250 mL) water into pan.
Roast in 500°F oven for 30 minutes. Reduce heat to 275°F; roast for 30 minutes. Stir honey with vinegar; brush one-third over roast. Roast, basting twice with remaining honey mixture, until thermometer registers 140°F for rare, about 40 minutes, or until desired doneness.
Transfer to cutting board; tent with foil and let stand for 10 minutes before slicing thinly across the grain.