Prepare teriyaki sauce: In a medium bowl, combine all sauce ingredients; whisk until combined and honey dissolves. Set aside.
In a large wok or skillet on high, heat 1 tsp grape seed oil, swirling to coat bottom of pan. Add chicken and sesame oil and stir-fry until browned, about 3 minutes. Transfer to a medium bowl.
Keep wok on high and heat 1 tsp grape seed oil. Add shrimp and stir-fry until pink, about 2 minutes. Transfer to bowl with chicken. Heat remaining 1 tsp grape seed oil in wok, and add bell pepper and broccoli; stir-fry until tender-crisp, about 1 minute.
Return chicken, shrimp and any juice to wok. Add corn and teriyaki sauce. Bring to a boil, reduce heat to medium, and cook, tossing occasionally, until chicken and shrimp are cooked through, vegetables are tender-crisp and sauce has thickened slightly, about 3 minutes. Sprinkle with scallions and chile (if using).