Scrub the potatoes, cut them in half lengthwise, then cut each half in thirds lengthwise. You'll have 6 long wedges from each potato.
Place the potatoes on a sheet pan with the olive oil, salt, pepper, garlic, and rosemary. With clean hands, toss all the ingredients together, making sure the potatoes are covered with oil.
Spread the potatoes in a single layer with 1 cut-side down.
Bake the potatoes for 30 to 35 minutes, turning to the other cut side after 20 minutes.
Bake until they are lightly browned, crisp outside, and tender inside.
