1.Heat 1 tbsp oil over medium heat, add chicken cubes, and toss until golden brown and cooked through. Drain and set aside.
2.In a pan, heat remaining 1 tbsp oil and sauté garlic until aromatic. Add sauce mix and stir until well combined. Add bell peppers and stir fry for about 2 minute. Add in fried chicken cubes and walnuts. Toss to evenly coat chicken cubes and walnuts with sauce.
3.Dish up and serve hot with rice or noodles.