Mix the dough: In a large mixing bowl, whisk together the sourdough starter, water, olive oil, and salt until combined. Gradually add the flour, mixing until a shaggy dough forms.
Knead the dough: Transfer the dough to a lightly floured surface and knead for about 5–7 minutes until it becomes smooth and elastic. If the dough is too sticky, add a little more flour, one tablespoon at a time.
Rest the dough: Place the dough in a lightly greased bowl, cover with a damp towel or plastic wrap and leave it on the counter for 12-24 hours. Overnight is ideal.
Divide and shape: Cut the dough into 12 equal pieces and roll each into a ball. Press with a cast iron tortilla press or roll out with a rolling pin to about 8 inches wide. You want them thin.
Cook the tortillas: Heat a dry cast iron skillet or nonstick pan over medium-high heat. Once hot, cook each tortilla for 30–45 seconds on one side until bubbles form, then flip and cook for another 20–30 seconds. The tortillas should have golden brown spots.
Keep warm and serve: Stack the cooked tortillas on a plate and cover them with a clean towel to keep them soft. Enjoy fresh or store in an airtight container for up to 3 days.