Spray crock pot with non-stick cooking spray. Place chicken cubes inside.
In a bowl stir sauce ingredients; soy sauce, hoisin sauce, balsamic vinegar, brown sugar, garlic, red pepper flakes. Pour sauce over chicken into slow cooker. Cook, covered, on high for 3 hours or 5 hours on low. STIR HALF WAY THROUGH COOKING.
About 15-20 minutes before serving, add peppers and zucchini. Whisk corn starch, cold water and Sriracha, then stir into crock pot. Cover, and continue to cook for 15 minutes on high or 25 minutes on low until sauce is thickened and veggies are tender-crisp.
Serve over rice garnished with peanuts and sliced green onions.