Marinating the Pork: Combine garlic, balsamic vinegar, salt, pepper, and olive oil in a gallon-sized Ziploc bag. Add pork to the bag and turn to coat each piece in marinade. Allow pork to marinate for at least 4 hours and up to 24 hours (the longer the better).
Thirty minutes before you are ready to begin cooking, remove the bag from the refrigerator and allow to rest.
Grill Preparation:Preheat grill to 400 degrees. Sear the pork on all sides (about 2 minutes on each side). Reduce the temperature to about 350 degrees, move the meat to indirect heat if possible, and grill for another 15-25 minutes (time will depend on the thickness of the loin pieces). Turn the pork over after 10 minutes. Using a meat thermometer, check the internal temperature. When the internal temperature reaches 140 degrees, remove from grill and tent with foil.
Let the meat rest 5 minutes before slicing (internal temperature will continue to rise while the meat rests).
Oven Preparation: Preheat oven to 400 degrees. Heat canola oil in a large, heavy, oven-safe sauté pan over medium heat. Add pork and sear on each side, about 2-3 minutes. Transfer pan to oven. Roast pork, turning occasionally, until the internal temperature is 140 degrees, about 20 minutes. Transfer pork to a cutting board, tent with foil, and allow to rest at least 5 minutes before slicing.