In a small bowl, combine the lemon juice, miso paste, soy sauce, and hot sauce until well blended.

In a large skillet, melt the butter over medium heat. Add the green beans and cook for a total of about 7 or 8 minutes, only flipping them a few times during the cooking process so that the beans get a nice bit of dark brown in spots where they are in contact with the pan. When they are cooked to your liking, and browned in a bunch of places, add the garlic, give everything a stir so that you can smell the garlic, and pour in the miso sauce. Flip the beans around in the miso until they are nicely coated with the sauce. Transfer to a plate and serve hot.