Mix the cassava flour and salt in a mixing bowl. Add the lard, then use a whisk or two knives to cut the lard into the cassava flour until the mixture resembles dry oatmeal; the largest pieces of lard should be no bigger than peas. (You can also use a food processor to do this job quickly, pulsing until the mixture resembles rolled oats.)
Add the apple cider vinegar and then the ice water 1 tablespoon at a time and work it into the dough. Stop as soon as the dough easily holds together. (In some climates, you may need an extra 1 to 2 tablespoons of water.)
Roll out immediately or wrap in plastic wrap and store in the fridge until needed (will keep for at least a week).
Use as you would for any recipe that calls for pie crust!
Recipe by The Paleo Mom at https://www.thepaleomom.com/perfect-pie-crust-aip/