How to Make It
Soak the rice noodles in a large bowl of cold water until pliable, about 10 minutes.
In a medium saucepan of boiling salted water, cook the edamame until tender, 5 to 6 minutes. Drain and rinse under cold water, then pat dry. Shell the edamame if necessary and transfer to a large bowl.
In a large saucepan of boiling salted water, cook the noodles, stirring, until tender, about 3 minutes. Drain, rinse under cold water and pat dry. Add the noodles to the edamame along with the pickled greens and fermented beans, and toss with 2 tablespoons of the oil.
In a bowl, whisk the water with the rice vinegar, mustard and the remaining 1/3 cup of oil. Add to the noodles and toss. Add the fresh mustard greens, season with salt and pepper and serve.