Trim the ends of the green beans and parboil the green beans for 2minutes.
Drain the water and cool the cooked green beans under the running water to avoid it being over cooked.
Grind the sesame seeds, peanut butter, sugar, and soy sauce in a sesame seed grinder bowl.
Add the cooked green beans and toss together until the sesame mixture coats the green beans well.
Serve in a small bowl.
Notes
I bought this sesame seeds grinder in Japan. If you don't have one of those, you can grind sesame seeds and other ingredients all together in a mortar and toss green beans and sesame seeds mixture in a large bowl.