In a small bowl, add the kung pao sauce ingredients together and whisk until combined. Set aside until later.
In a large bowl, combine the 1/4 cup soy sauce and the cornstarch. Whisk until completely smooth and no clumps remain. Add all the chicken slices and toss until all of the chicken is well coated in the marinade.
In a large cast iron skillet, heat 2 tbsp of sesame oil over high heat. Once the pan is hot and the oil is simmering, stir fry the chicken strips in 3-4 batches; it should only take a minute or two per side. If you have a thermometer, make sure the chicken reaches an internal temperature of 165°F. Once the chicken is cooked, remove from the pan and set aside for the moment.
In the same pan, add the last tbsp of sesame oil. Once the oil has heated up, add the bell peppers and stir fry for 4-5 minutes, the bell peppers should begin to soften and brown. Add the green onions, chili peppers, garlic, ginger, and cashews. Stir fry everything for another ~2 minutes and then add back the chicken and the kung pao sauce prepared set aside in the beginning. Let the sauce simmer and thicken for a few minutes, stirring occasionally to make sure everything is getting evenly coated.
Once done, remove from the heat and serve immediately. Garnish with sesame seeds and enjoy!
