Peel and cube the potatoes so they are about 1 cm square. Coat with olive oil. Sprinkle in spices.
Preheat oven to 400*F. Bake for about 30 minutes, turning every 10-15 minutes.
Sweet potatoes tend to stay pretty soft. If you do these with Russet potatoes, they need longer to cook (about an hour) and tend to get a bit crusty on the outside which makes for a nice contrasting texture.