Heat 2 Tbsp. of the oil over high heat in a large skillet or wok. Coat chicken in cornstarch, shake off excess, and then add to the skillet. Cook 3-4 minutes, or until chicken is cooked through. Remove and reserve. Add remaining oil to the pan. Add garlic, ginger, pineapple, asparagus and cherry tomatoes and stir-fry 2 minutes. Add teriyaki sauce, cashews, and cooked chicken. Stir-fry 2-3 minutes more. Sprinkle with chopped cilantro or green onions and serve with steamed rice.