On a large sheet of aluminum foil, shiny side up, place the pork loin. Rub it with the canola oil and crimp the sides to make a bowl all around it making certain to leave enough foil to close over the roast.
Pour the water into the aluminum foil pouch.
Rub the honey and mustard over the top of the pork. Add the minced garlic, salt, and pepper.
Pour the diced tomatoes over the top.
Seal the aluminum foil pouch around the roast and place it on a roasting sheet or in a pan to catch any juices that might escape. Place it in the oven and roast it for 6 hours.
Remove the pork from the foil pouch, saving the juices and tomato bits in another dish, and cool the meat to room temperature. NOTE: The finished pork will not have much color as it was not seared or browned before the long, slow cooking process.
In a skillet, cook the juices and tomatoes over a medium heat until reduced to a glaze. Pour this glaze over the pork roast and place in the refrigerator.
Shred or slice the pork into very small pieces for use on sandwiches, in omelets, or other applications.