Potatoes soak up smokiness and crisp so well under high heat, it’s tempting to toss them on the grill. But that can be a challenging affair; even small potatoes tend to scorch outside before becoming tender inside. Seeking a solution, we found that parboiling small skin-on potatoes—about 1½ inches round—prior to grilling is key. And after many batches, we learned that for best flavor and texture, the water for parboiling should be salted and acidulated. The salt enhances flavor, while the acid (we like white vinegar) helps the potatoes hold their shape while the insides become at once fluffy and creamy. When it was time to grill, a sturdy perforated metal grill basket with a broad bottom is best for managing the potatoes over the fire. The basket also provides a flat heat-conducting surface that helps with browning. If you don’t own a grill basket, not to worry: the potatoes can go directly on the grate, but you’ll need to be more vigilant about turning them with tongs. Though they may brown and char spottily, the flavor still will be great. Hot off the grill, we toss the potatoes in a simple dressing of grainy mustard (for texture) and Dijon mustard (for clingability), plus another splash of vinegar and green herbs for bright, fresh flavor. Serve warm or at room temperature alongside grilled meats, vegetables or seafood.