How to Make It
Light a grill. Wrap each potato in a double layer of foil and arrange them around the hot coals; the potatoes should be close to, but not touching, the coals. Roast the potatoes for about 1 hour and 15 minutes, until tender, turning them halfway through. Discard the foil, then brush the potatoes lightly with vegetable oil and season with salt. Grill the potatoes directly on the grate over moderately high heat for about 4 minutes per side, or until the skin is crisp. Split the potatoes in half crosswise, and top with butter. Serve with the Salsa Verde alongside.