VELVET THE CHICKEN: Cut the chicken into small, bite-sized pieces (roughly ¾ inch). To a large bowl, add the chicken, water, soy sauce, kosher salt, baking soda, egg white, white pepper, and egg whites. Stir to combine.
COAT: Then add the rice flour or corn starch to the same bowl and stir to coat all of the chicken evenly.
SAUCE: in a small bowl or measuring cup, combine all the ingredients for the sauce. Add 1 tablespoon of water and stir together until most of the brown sugar dissolves.
FRY: add 2 tablespoons of oil to a deep large skillet over medium-high heat. Add ½ of the chicken ones the oil is hot and cook on one side undisturbed for 2-3 minutes before flipping and cooking the other side for another 2-5 minutes. When the chicken is golden and cooked, remove to a plate. Add more oil as need and cook the remaining chicken in batches. Remove all the chicken from the pan.
TOSS: Drop the skillet temperature to medium low. Stir and pour the prepared sauce into the pan and when it starts to sizzle, add the crispy chicken pieces back to the skillet. Stir to combine so that all the chicken is coated in the sauce. Remove from heat. Top with tons of sesame seeds.
SERVE: over a bed of fluffy rice with steamed broccoli on the side. Leftovers store well in an airtight container in the fridge for 3-4 days.