Marinate the Protein:
Toss chicken and shrimp with soy sauce, cornstarch, and sesame oil. Let sit for 10–15 minutes while prepping vegetables and sauce.
Make the Sauce:
In a small bowl, whisk together soy sauce, oyster sauce, hoisin, rice vinegar, sugar, chili paste, water, and cornstarch. Set aside.
Stir Fry Chicken and Shrimp:
Heat 1 tablespoon of oil in a wok or large skillet over high heat. Stir fry chicken until nearly cooked, about 3 minutes. Add shrimp and cook until just pink, 2–3 minutes. Remove both from the pan and set aside.
Stir Fry the Veggies:
Add remaining oil to the pan. Stir fry garlic, ginger, and vegetables for 3–4 minutes until crisp-tender.
Combine Everything:
Return chicken and shrimp to the pan. Stir sauce once more, then pour over everything. Stir well and cook 1–2 more minutes until sauce thickens and everything is coated.
Serve:
Garnish with green onions and serve immediately over steamed rice or noodles.