Wash your sweet potato and cut it into 5 mm wide slices, lengthwise. You can cut them with a regular knife or slice them with a meat slicer, just watch your fingers as they sometimes can be a little bit tricky to cut. Try not to make them any wider than 5 mm or you will have troubles getting them to fully cook.
Crank up the heat of your toaster as much as you can and toast each slice 2-3 times. Your sweet potato toasts will turn slightly brown and get a thin crunchy crust, they are done when they are slightly soft in the middle.