Ingredients

• 1 1/2 tablespoons olive oil
• 2 lb russet (baking) potatoes (preferably organic; about 4 medium)
• 1 teaspoon kosher salt
• 1/4 teaspoon black pepper
• 1 1/2 tablespoons unsalted butter
• 1 teaspoon finely chopped fresh rosemary

Instructions

1. Put oven rack in lower third of oven and preheat oven to 500°F. Oil bottom of a shallow baking pan (15 by 10 by 1 inch) with 1/2 tablespoon oil.
2. Cut each potato lengthwise into 8 wedges and toss with salt, pepper, and remaining tablespoon oil in a large bowl. Arrange potato wedges, flat sides down, in baking pan, then cover pan tightly with foil and roast 10 minutes. Remove foil and roast 10 minutes more. Loosen potatoes with a metal spatula, then turn over onto other flat sides and roast until tender and golden, about 10 minutes.
3. While potatoes roast, melt butter with rosemary in a small saucepan over moderately low heat. Loosen potatoes with spatula, then transfer to a serving dish or plates and spoon rosemary butter over them.