Preheat oven to 400°.
Bring meat to room temperature (takes about an hour).
Spray roasting pan with cooking spray.
Insert garlic slivers into the top of the meat.
Whisk together vinegar, oil, and mustard. Reserve half for dipping sauce and rub the other half over the roast with your fingers.
Top with sage and rosemary.
Cook for approximately 50 minutes (check after 30 minutes) or until the meat thermometer reads 145-150°.
Let sit for 10 minutes slightly tented with foil before carving.