Add the flour, purple sweet potato powder and salt to a large bowl and mix until thoroughly combined.
Add the lard and rub it against the flour using your fingertips until it resembles coarse bread crumbs.
Add the hot water, a little at a time and working it in with your hands until the dough just comes together. The amount will vary mainly depending on the flour you’re using and your humidity (and remember we still have to add the starter!).
Work your sourdough starter into dough and knead it on the counter until it comes together into a smooth dough (takes just a minute or two). And if your dough is too tacky feel free to add a touch more flour (conversely if it feels crumbly go for a bit more water).
Transfer to a bowl (or ziplock bag) and allow it to ferment at room temp anywhere from 3-12 hours, noting that the longer you let it go the more your culture will have worked its way through the flour (i.e. less gluten and *much* less carbs, if that’s what you’re going for).
Heat up a skillet (preferably) or pan over medium heat. You can test the heat by sprinkling a few water droplets, if the drops evaporate immediately your pan is too hot. The droplets should ‘run’ through the skillet.
Break the dough into eight balls and roll out between two sheets of parchment with a rolling pin or using a tortilla press (easier!) until the dough is ultra thin (even lightly translucent)
Cook over medium heat for just 3-6 seconds until the dough is *just* sealed on the first side (very important to get your tortillas to puff up!). Flip it over immediately (using a thin spatula or knife), and continue to cook until just lightly charred, say 30 to 40 seconds on each side. The key is not to overcook them, as they will no longer be pliable or puff up.
Keep them warm wrapped in a kitchen cloth until serving. And to rewarm, heat briefly on both sides (less than a minute).
Tortillas are best enjoyed fresh off the stove, so feel free to keep some dough handy in your fridge for up to five days (but they also freeze well ready-made for up to three months).
Video
Notes
*please note that all sourdough recipes on the site are developed around King Arthur's Organic Bread Flour (for consistency sake)(and because its my personal favorite "generic" flour to bake sourdough with)(but I generally also test all the recipes with other heirloom & heritage flours– Hayden Flour Mills makes some of my favorite blends).