Stir together the maple syrup, mustard vinegar, soy sauce, salt, and pepper in a small bowl. Set glaze aside.
Place pork roast in a shallow roasting pan. Spread glaze evenly over pork roast.
Roast pork in a 350 degree F (175 degree) oven. Cook until internal temperature measured with a meat thermometer reaches 160 degrees, about 1 hour. Remove from oven, and let rest about 10 minutes before slicing.
To Freeze: Freeze slices in freezer safe container.
To Reheat: Reheat in microwave or in oven until cooked through.