1. Yams - peel and cut into 1/2 inch thick slices.
2. When the grill is hot, lightly oil the grate. Coat the strips of yam with olive oil cooking spray and season with salt.
2. Arrange the yam strips on the grate crosswise so they don't fall through. Cook for 10 to 12 minutes per side, until tender and glazed. Serve with butter.