1Heat gas or charcoal grill. In small bowl, mix sauce ingredients; set aside.
2Cut each sweet potato lengthwise into 4 or 5 slices; brush both sides with oil. Carefully brush additional oil on grill rack. Place potatoes on grill over medium heat; sprinkle with 1 teaspoon of the salt.
3Cover grill; cook 8 to 10 minutes, turning once and sprinkling with remaining 1 teaspoon salt, until potatoes are tender. Serve with sauce.