Preheat the oven to 300°F.
Slice the sweet potatoes into thin 1/8-inch pieces using a mandolin or knife. Ensure the slices are thin for a crispy texture.
Line a baking sheet with parchment paper and arrange the slices on it.
Spray the slices with coconut oil, sprinkle with sea salt, and bake for 20 minutes at 300°F.
Flip the slices and bake for an additional 20 minutes.
Check for firm slices and remove them to cool on a wire rack. If any slices are still soft, bake them for 10 more minutes, avoiding burning.
Continue baking in short intervals until all the chips have hardened. Allow them to cool thoroughly on the rack.