Bring a large pot of salted water to a boil and trim the green beans. Add the green beans to the boiling water and cook until crisp-tender, about 4 minutes. Drain in a colander, rinse under cold water and drain again. Refrigerate.
In a food processor, pulse the peanuts until coarsely chopped. Reserve 1/3 cup of the chopped peanuts for garnish. Continue pulsing the remaining peanuts until finely chopped. Add the vinegar, ginger, garlic, soy sauce, sugar, oil, 2 tablespoons of hot water and 1 teaspoon of salt to the peanuts and blend until the dressing is almost smooth, scraping down the sides of the bowl several times.
Toss the green beans with the dressing. Sprinkle the reserved chopped peanuts over the green beans just before serving.