Heat a nonstick pan over medium high heat. Once hot, add the oil. Sauté the onion and peppers until they start to soften and brown. Add the garlic, ginger, and red pepper flakes (use sparingly or not at all if you don't want it spicy). Sauté until the garlic and ginger start to become golden brown. Then add in the the chicken and brown well all over.
Turn down the heat to medium, stir in the rice wine vinegar, soy sauce, oyster sauce, molasses, and broth. Bring to a low simmer.
Add the cornstarch mixture a little at a time until the sauce has a thickened creamy consistency (if needed add more cornstarch/water slurry until it reaches the desired consistency).
Garnish with scallions, nuts, and fresno pepper (if desired).