Bring a pot of salted water to a boil. Snap the ends from the greens beans and drop into the water. Blanch the beans until bright green and just tender, 4 or so minutes. Transfer the green beans to an ice bath and let cool.
Place the green beans in a bowl along with the crushed walnuts. In a separate bowl combine the ingredients for the dressing, whisking to combine. Pour over the green beans and toss until well combined.
Tips & Tricks: To toast the walnuts, place in a dry skillet over medium-low heat. Cook, shaking the pan often, until the walnuts are fragrant and starting to brown.