Cook Potatoes: Preheat oven to 425 degrees F (220 degrees C). Line baking pan or sheet with foil, if cooking sweet potatoes. Pierce each potato with a fork several times. Place potatoes on baking pan and bake for 45 to 60 minutes, depending on how big they are. You should be able to cut through the potatoes easily. I used potatoes that were about 7 to 8 ounces (200 to 225 grams), and they cooked in about 45 minutes.
Cook Chicken: Place chicken in a medium saucepan. Sprinkle salt on top and add water to cover chicken by about an inch. Bring water to boil. Reduce heat to medium or medium-low, and let chicken simmer for about 10 to 15 minutes. The chicken is ready when it is no longer pink in the middle or when your meat thermometer reads 165 degrees F (75 degrees C) at the thickest part. Let chicken cool on a plate and shred it using two forks or with your hands.
Prepare Sauce: Mix 1/2 cup water, tamari sauce, agave, and sherry together. In another bowl, stir potato starch with 2 tablespoons water. Heat oil in a sauté pan over medium-high heat. Add garlic and ginger and cook for a minute. Add red pepper flakes and tamari sauce mixture and let it cook for 1 to 2 minutes. The sauce should bubble vigorously. Give potato starch mixture a quick stir and add to the pan. The sauce should start clumping up. Stir sauce for another minute. Add chicken and peanuts to pan and coat sauce over them. Turn off heat.
Cut open each potato in half and fill it with the kung pao chicken. Top with sliced green onions and sesame seeds, if you like.