Add water and melted butter to your stand mixer and whisk in the sourdough discard
Next add the flour and salt and with the dough hook, set your stand mixer to medium and mix until the dough comes together, it should clean the sides of the bowl, turn the mixer to low and allow it to knead for a couple minutes.
Turn the dough out onto the counter and divide it into ten equal portions, about 72 grams each, roll them into balls, then gently press down on them to flatten and cover them with a tea towel for about 30 minutes
When you are ready to cook the tortillas, lightly grease your cast iron and set it to medium high heat, then one at a time roll out a tortilla, using as much flour as you need to make sure it doesn't stick to the counter.
Add the rolled out tortilla to the pan and cook until bubbles start forming on the top surface, flip them and cook for about 15 more seconds, Roll out the next while the previous one is cooking and repeat. If you start to get little burn patches on them instead of light brown, just turn down the heat.
Whichever ones you don't use and wrap in plastic wrap and put in the fridge.