Sweet and tangy balsamic vinegar makes a great marinade for this roast pork loin recipe. As the pork loin roasts, the marinade is used as a basting liquid, and when the meat's cooked it's served as a delicious sauce with the tender slices.
In a small mixing bowl, whisk together all the ingredients, except the pork loin. Place the pork into a plastic freezer bag and pour in the marinade. Press out air, seal the bag and marinate the pork for 3 hours.
Preheat oven to 350 F. Place the pork in a baking dish, season with additional salt and fresh ground black pepper to taste, and pour in the marinade. Add 1/2 cup of water, and place in the preheated oven. Roast for about 1 hour, basting occasionally with the marinade until the internal temperature reaches 145 to 150 F. Remove and let the pork loin rest for 10 minutes before serving. Slice and serve with some of the marinade drizzled over the top.
Note: the marinade can be reduced in a saucepan while the pork is resting, if a thicker, more intense sauce is desired.