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 it with a damp towel or plastic wrap, and let it rest at room temperature for 12–24 hours. This fermentation period enhances the flavor and improves the dough’s flexibility.
Divide and shape: After resting, cut the dough into 12 equal pieces and roll each into a ball. Lightly flour a surface and roll each ball into a thin circle, about 8 inches in diameter.
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.