Heat the lard in a cast iron pan over medium heat.
Use a mandolin to slice the sweet potato into thin rounds. If you do not own a mandolin, slice it as thin as you can with a large knife.
Once the lard is hot, drop in the sweet potato slices in small batches (to avoid overcrowding the pan).
Flip them over occasionally using tongs and continue cooking until they are browned and crispy (approx. 5 minutes but cooking time may vary).
Carefully remove the chips from the oil and drain on a paper towel to soak up any excess grease.
Apply salt (to taste) while chips are still hot and enjoy them immediately with your dip of choice!
Store any leftovers in an airtight container in the fridge, but definitely eat them up within a day or two. To get them nice and crunchy again, toast them in your toaster oven or regular oven.