Rub the salt and pepper over the pork tenderloin. If you are pan searing it, heat 2 T olive oil in a skillet over medium high heat. Let each side get very dark brown about 1-2 minutes. Add ½ cup of water to the crockpot and place the pork inside.
Cook the pork on low for 6-8 hours. The last hour of cooking, in medium saucepan mix together garlic, ½ cup water, brown sugar, cornstarch, balsamic vinegar, and soy sauce together. Bring to a boil and reduce the heat to medium low and stir until the glaze thickens. Slowly add more cornstarch if needed.
Brush the roast with the glaze 2-3 times the last hour of cooking. To get the caramelized crust, remove the pork roast from the crockpot and place on an aluminum foil lined pan. Brush more of the glaze on top and broil on high for 2-3 minutes until the desired crust is achieved.
With two forks shred the pork. You can serve with rice, potatoes, or in sandwiches. Serve with remaining glaze on the side.