In a small saucepan over medium heat, add the butter and water. Heat just until the butter, tallow, or lard is melted. (skip this step if using oil)
In a large bowl, add all the dry ingredients and stir them together. Then add in the sourdough discard and melted butter/water mixture. Mix until the dough is shaggy.
Turn the dough onto the counter lightly dusted with flour and hand knead for 3-5 minutes until it forms into a smooth ball.
Cover the bowl with a damp towel and let it sit for 30 minutes. (Can be wrapped with plastic wrap and stored in fridge for up to a week for longer fermentation)
Cut the dough into 12-16 equal wedges, then roll them into a ball. (I do 16 so I can roll them thin without making them too large. Think “soft taco” flour tortilla size from the store)
Cover and rest for 10 minutes.
Then take a rolling pin and roll them out. They likely won't roll very thin at first, so what I do is roll them all as flat as they'll stay, then roll them again into an 8" (ish) circle right before I cook them. I roll the next one while one is cooking. (Also see tips below for shaping)
Heat a cast iron skillet over medium heat. Then add the flattened tortilla. Cook for 30-60 seconds until bubbles start to appear, then flip and cook for another 30 seconds. Set on a plate and cover with a tea towel.