In a large bowl, whisk together 3 teaspoons of the soy sauce, 2 teaspoons of the sherry, 2 teaspoons of the cornstarch, and salt. Add the chicken, toss to coat, cover, and let stand for 30 minutes.
Make the cornstarch mixture
Meanwhile, in a small to medium bowl, whisk together the remaining 3 teaspoons coconut aminos, 3 teaspoons sherry, the red wine vinegar, chicken broth, sugar and remaining 1 teaspoon of cornstarch. Set aside
Cook the kung pao chicken
Heat a wok or a large skillet with high sides over medium heat, then add 1 tablespoon of the oil. Add the peanuts and cook, stirring regularly, for about 2 to 3 minutes. Once the peanuts are golden brown, remove from the pan and set aside on a bowl or plate.
Add the remaining 2 tablespoons of oil to the wok. Add the chili peppers and stir-fry just until they begin to lightly char, about 1 minute.
Add the chicken and stir-fry for 2 to 3 minutes, lightly browning all sides. Add the ginger and stir-fry until the chicken is cooked through, about 1 minute more. Add the green onions and peanuts, then pour in the cornstarch mixture and stir until the sauce boils and thickens, about 1 to 2 more minutes.
Garnish with sesame seeds and red chili flakes, if desired. Serve immediately.
Notes
STORAGE: Store leftovers in an airtight container in the refrigerator for up to 4 or 5 days. CHICKEN: You can use boneless, skinless chicken breasts or thighs. Be sure to cut the chicken into equal size pieces so that they cook evenly. COCONUT AMINOS: Coconut aminos are naturally gluten-free and lower in sodium than soy sauce. You can substitute soy sauce if you don't need/want a gluten-free dish.CORNSTARCH: Pure cornstarch is naturally gluten free. You can substitute arrowroot powder, tapioca starch, or potato starch for cornstarch.