Mix the sage, pepper and garlic together and rub on the tenderloin. Pour ½ cup of water in the slow cooker and place the tenderloin inside. Cook on low for 6-8 hours.
Mix together the other ½ cup of water with the brown sugar, corn starch, balsamic vinegar and soy sauce in a small saucepan. Heat over medium heat and stir until it thickens. Brush on the tenderloin just before serving.
Recipe by Couponing to Disney at https://www.couponingtodisney.com/pork-tenderloin-slow-cooker-recipe/