*Be sure to buy young arugula, which has a feathery texture. Mature arugula sold in bunches is too pungent. Substitute any young greens, such as baby spinach or mixed greens.
Make-ahead tips: Bake the sweet potatoes and make the dressing ahead of time and refrigerate for up to 2 days. Reheat the sweet potatoes to room temperature in the oven before assembling the salad.