This is a great side dish to make as part of a larger Japanese feast because it can be made quickly and set aside until needed while you work on more complex dishes. Green beans are parboiled and mixed with a simple sesame miso dressing.
Toast the white sesame seeds in a dry saucepan over medium heat for a few minutes or until they are beginning to brown. Don't let them burn. Transfer to a mortar and pestle or spice grinder and roughly grind them.
Cut the beans in half, and blanch them in salted boiling water for a couple of minutes until they are just tender. Drain and rinse with cold water.
Add the miso to the sesame seeds and mix into a paste. Add the sugar and mirin and mix.
In a mixing bowl combine the beans and miso dressing and mix until the beans are well coated. Serve at room temperature in individual bowls.