Cut the sweet potatoes into thick strips. Soak them in a bowl with water for 30 min. Dry them well and roll them in a bowl with the corn starch, while stirring with your hands.
Pour in the olive oil, brown sugar and remaining spices and roll the potatoes again well with your hands.
Arrange the potatoes in a tray laid out with baking paper. Bake the sweet potatoes for 30 min. at 356°F (180 °C).