Ingredients

Coarse salt and freshly ground pepper

1 1/2 pounds red potatoes, scrubbed well and sliced 1/2 inch thick

1 1/2 pounds sweet potatoes, scrubbed well and sliced 1/2 inch thick

1/4 cup extra-virgin olive oil

6 sprigs rosemary, leaves removed and crushed

Preparation

Bring a large pot of water to a boil. Add 2 tablespoons salt and the red potatoes. Return to a boil. Reduce heat, and simmer until just tender, about 7 minutes. Remove potatoes using a slotted spoon. Return water to a boil. Add sweet potatoes, and simmer until just tender, 4 to 7 minutes. Drain. Gently toss red and sweet potatoes with oil and rosemary; season with salt and pepper. Refrigerate for 1 hour.

Heat grill to medium-high. Gently toss potatoes, and transfer to grill; reserve bowl with oil. Grill potatoes, turning occasionally, until charred and heated through, 6 to 7 minutes. Brush potatoes with oil from bowl.