In a microwave-safe bowl, mix the cornstarch with the water.
Microwave the mixture for a few minutes, whisking often until it thickens into a paste.
Cut the potatoes into wedges.
Coat the potato wedges with the cornstarch paste, making sure they are fully covered.
Arrange the coated wedges on a baking sheet in a single layer.
Bake in a preheated oven until the water in the paste evaporates and the wedges form a thin, crispy crust.
Take them out of the oven and serve hot.
