In a large resealable bag, combine nondairy milk, garlic, and red pepper flakes. Add chicken. Marinate for 15-20 minutes at room temperature to tenderize the chicken.
Place potato starch into a large bowl. In a second large bowl, whisk egg whites until soft peaks form.
Dredge marinated chicken in the potato starch, then coat with a thin layer of egg whites, scraping against the side of the bowl to remove excess (see note). Discard remaining marinade.
Heat 3 inches of oil over medium-high heat. Working in batches, add chicken, taking care not to crowd the pan and making sure each piece is fully submerged in oil. Fry for 2 minutes until golden.
Transfer chicken to a paper towel-lined 9x13-inch pan.
Prepare the sesame-less sauce: In a small bowl, whisk together sauce ingredients until smooth. Transfer to a large skillet; bring to a boil, stirring constantly, until sauce thickens. Add fried chicken; toss to coat. Serve warm.
Notes
If beaten egg whites become liquid, whisk again to form soft peaks.