Whisk all of the ingredients for the sauce in a large measuring cup or mason jar. (Only add 1 Tbsp. cornstarch into the sauce, reserve the other Tbsp. for later).
Place the pork tenderloin in a slow cooker.
Pour the sauce over the pork. Spoon some of the sauce on top of the pork to coat. Cook on low for 4-6 hours or on high for 3-4 hours. (Internal temperature using a meat thermometer should read 145°F)
Remove the pork from the slow cooker and place on a cutting board. Cover with foil to keep warm.
Carefully pour the liquid from the slow cooker into a medium sized saucepan. Use an immersion blender to smooth out the sauce if preferred.
Heat the sauce over medium heat and bring to a simmer. If you prefer the sauce to be thicker, stir together the remaining 1 Tbsp. cornstarch with 1-2 Tbsp. water to create a slurry. Whisk into the sauce and simmer for about 1 minute or until sauce thickens. Remove from heat.
Slice or shred the pork, pour sauce over the pork and serve with rice and veggies.
Serve with roasted broccoli, asparagus, brown rice, cauliflower rice, Brussels, etc.