Marinate the Chicken : In a medium bowl, combine chicken pieces with cornstarch, soy sauce, rice vinegar, and sesame oil. Mix until well-coated. Let marinate for 10-15 minutes.

Prepare the Sauce : In a small bowl, whisk together soy sauce, hoisin sauce, oyster sauce, rice vinegar, honey, sesame oil, chicken broth, and cornstarch slurry. Set aside.

Cook the Chicken : Heat 1 tbsp of olive oil in a large skillet or wok over medium-high heat. Add the marinated chicken and stir-fry for 5-6 minutes, or until the chicken is golden brown and cooked through. Remove the chicken from the skillet and set aside.

Stir-Fry the Vegetables : In the same skillet, add 1 tbsp of vegetable oil. Stir-fry the onion and red bell pepper for 3-4 minutes, or until slightly tender. Add the minced garlic and ginger, and cook for 1 minute until fragrant.

Combine Chicken and Sauce : Return the cooked chicken to the skillet with the vegetables. Pour in the sauce and stir to combine. Cook for 2-3 minutes, stirring occasionally, until the sauce thickens and evenly coats the chicken and vegetables.

Add Cashews and Garnish : Stir in the toasted cashews. Taste and adjust seasoning if needed. Remove from heat and garnish with chopped green onions.

Serve : Serve hot over steamed rice, quinoa, or noodles for a complete meal.