Shaved Fennel, Potato and Arugula Salad with Mustard-Dill Dressing
To make salad, place potatoes in a large bowl and toss with half of dressing. Arrange dressed potatoes on a 24" x 18" piece of heavy-duty foil and seal shut. Move foil pouch to a baking sheet and bake until potatoes are tender when pierced with a knife, about 35 to 45 minutes. Remove, allow steam to escape, and cool to room temperature.
Return potatoes to large bowl, add fennel and arugula, and toss with remaining dressing. Serve at room temperature or chilled.