Snap off both ends of the green beans, rinse in cold water and drain. Heat vegetable oil in a large wok or pan over high heat. Carefully, add green beans, they will splatter in the hot oil; stir-fry for 2 minutes. Add minced garlic, hoisin and oyster sauces; stirring to combine. Cook for 1 additional minute. Pour into a serving platter, garnish with cashews.