Place the green beans in a large saucepan or pot with one inch of water. You may place them in a steamer insert if you have one. Bring to a boil, cover and cook for 5 minutes, they should still be firm and bright green.
In a small bowl, stir together the soy sauce, balsamic vinegar and sugar; set aside.
Heat the sesame oil in a large skillet over medium heat. Add garlic and cook until starting to brown. Add the green beans and stir to coat with the oil. Stir in the soy sauce mixture and simmer for a couple of minutes uncovered to reduce the sauce. Transfer the beans to a serving dish and pour the sauce over them.
