In a small bowl, whisk together all marinade ingredients and pour over the pork. Either store in a Tupperware or bag and refrigerate for at least 2 hours or overnight.
Heat your grill so one side is high heat and the other side is low. Remove the tenderloin from the marinade but don’t dump out the liquid! We will need it later.
Brown the tenderloin on all 4 sides for about 1-2 minutes on the high heat side. Move over to the low heat side and cook for about 5 minutes on each larger, flatter side until the internal temperature is 145 degrees. You can also sear it on a HOT cast iron for 2-3 minutes each side then bake at 400 degrees for 10-12 minutes if you do not have a grill.
While the pork rests (10-15 min), make the kung pao topping. In a sauté pan over medium/high heat, add your sesame oil then the bell pepper, onions and peanuts. Sauté for about 6-8 minutes or until veggies begin to soften and char slightly. Add in the remaining marinade and your tapioca flour to thicken (optional). Let it cook for another 2-3 minutes.
Slice your pork into thick medallions and top with the Kung Pao mixture. I served over green beans with steamed rice.
