This potato salad is my favorite way to use chimichurri sauce. Make a big batch of chimichurri sauce to marinate steak or chicken for the grill. Then use what's leftover to make this potato salad, and you'll have the perfect side dish. The flavors of chimichurri taste sweeter and more mellow when mixed with mayonnaise, and the flecks of parsley and cilantro look great with the red skinned new potatoes. You could add some red pepper or celery for crunch, or even some sweet pickle.