Preheat your oven to 450. Scrub your sweet potatoes, don't peel them. Slice them as thinly as you can - a mandoline is good for this. Coat a baking sheet with olive oil. Arrange the sweet potato rounds in one layer on the sheet. Sprinkle salt and pepper to taste, and bake for 15 to 20 minutes, or until they're crispy and golden brown.
Head over to the original recipe at Edible Aria for a good variation on this using rosemary!