In a thick bottom frying pan, grill the sasame seeds at medium heat, shaking it from time to time, for 3 minutes or until they're golden. Set aside.
In a non-stick frying pan with cover, heat the oil at medium heat. Add garlic, ginger, salt and pepper and cook for about 30 seconds or until garlic and ginger begins exit their aroma. Add green beans and cook, stirring, for 2 minutes. Add vegetable stock, cover and cook 6 minutes. Remove the cover and keep on cooking for about 2 minutes or until the liquid is evaporated and green beans are tender but still crisp. Sprinkle with sesame seeds.