Preheat oven to 375°F.
Combine all ingredients for the sauce in a small bowl and whisk together.
Place the chicken, cashews and veggies in a medium bowl or right into an oil sprayed baking dish. Season the chicken generously with salt, pepper, and optional garlic powder.
Pour sauce over chicken and veggies and toss to coat. Transfer to a baking dish if you haven't done so already.
Place in oven and bake for approximately 20-24 minutes, or until chicken reaches an internal temperature of 165°F.
Allow to sit for several minutes to absorb flavor and sauce to thicken slightly.
Serve over rice or as desired with a sprinkle of sesame seeds.