Preheat oven to 375F degrees. Spread one tablespoon of the olive oil on a cookie sheet. Add the russet potatoes, rosemary, and olive oil in a bowl. Mix well to coat all the potato cubes.
Place the potatoes on the cookie sheet and sprinkle generously with the salt. Bake in the oven and cook for 30 minutes or until the potatoes have formed a nice crust on the bottom and are golden on top.