Difficulty: Easy - for beginners
1/4 stick (4 tablespoons) butter, cut in pieces
1/8 cup olive oil
4 medium Russet (baking) potatoes (3 pounds), scrubbed and cut lengthwise into 8 wedges each
1/4 teaspoon salt
Preheat the oven to 450F.
Put the butter on a very large (12- by 17-inch) shallow baking sheet (or two smaller ones) and put pan in the oven just until the butter melts. Remove from the oven and let cool slightly.
Add the olive oil to the butter, then put the potatoes in the pan and toss with fingers to coat. Sprinkle with salt and toss again. Arrange the potatoes in a single layer and put in the upper third of the oven (or the upper and lower thirds if using 2 baking sheets, and switch positions halfway through baking). Bake until the undersides are golden, about 30 minutes, then turn wedges over and bake until tender and crisp on the edges, 10 to 15 minutes more.