Heat vegetable oil in a large skillet over medium high heat.
Sprinkle the salt and pepper over the chicken chunks and mix to coat the chicken.
FOR THE CRISPY CHICKEN: Place flour in one bowl and buttermilk in another. Working a few chicken pieces at a time; dredge chicken in flour, dip into buttermilk, then dredge in flour again.
In a few batches, add chicken to the skillet and cook until evenly golden and crispy, about 4-5 minutes on each side. Transfer to a paper towel-lined plate to let drain and cool. Repeat with remaining chicken chunks.
FOR THE SAUCE: In a small bowl, mix together cornstarch and 1 tablespoon water, set aside.
In a small saucepan over medium high heat, combine honey, water, soy sauce, rice wine vinegar, sesame oil and red pepper flakes (if using). Bring to a boil; reduce heat to low and stir in cornstarch mixture. Let cook, while stirring occasionally, until slightly thickened; about 2-3 minutes. Reserve 1/4 cup of sauce for drizzling.
Move cooked and crispy chicken to a mixing bowl and immediately pour the hot Asian honey sauce over the chicken. Gently stir to coat the chicken in the sauce.
Serve the chicken over cooked rice and drizzle with the reserved 1/4 cup honey sauce.