Black Olive and Roasted Potato Salad with Arugula

I love a potato salad that is not mayo-based. The lemon, sherry vinegar, and arugula offset the briny-ness of the olive tapenade in this recipe. Feel free to substitute any variety of white potato you have lying around, but including the sweet potato is crucial. If you don’t have the time or inclination to make your own olive tapenade, simply use ½ cup (135 g) of store-bought olive tapenade in place of the olives puréed in step 2 below.