In a medium bowl, combine the flour and salt by whisking them together.

Use the back of a fork to cut the softened butter into the flour until it is well mixed and incorporated. If needed, you can use your hands to help blend the butter into the flour.

Add the water and sourdough starter to the mixture, and use a spatula to combine everything until a shaggy dough forms.

If necessary, gently knead the dough in the bowl with your hands until it forms a rough ball.

Transfer the dough to a floured surface and knead for an additional 1 to 2 minutes until it becomes smooth and no longer sticks to the surface.

Divide the dough into 12 pieces for taco- or enchilada-sized tortillas, or 6 pieces for burrito-sized tortillas. Shape each piece into a ball.

Cover the dough balls with a light kitchen towel or plastic wrap, ensuring the room temperature is not too hot.

Allow the dough to rest for 30 minutes up to two hours at room temperature, or refrigerate for up to 24 hours in an airtight container if needed.

Roll each ball out to a diameter of about 6 to 8 inches for taco size or 10 to 12 inches for burrito size, rolling them as thinly as possible until you can see the counter through the dough.

Heat a 12-inch non-stick or cast-iron pan over medium-high heat without adding any oil.

Place a tortilla in the pan and cook until it puffs and develops little brown spots on the underside.

Flip the tortilla using tongs or your fingers and cook the other side until it is lightly browned. Each tortilla should take about 60 seconds to cook.

If you prefer a bit of char, keep the tortilla in the skillet until both sides are charred.

Note that the first 3 to 4 tortillas may appear pale due to the skillet not being fully heated. As you continue cooking, adjust the heat as needed to achieve your desired level of char.

Once the tortillas have cooled, store them in an airtight bag or container at room temperature for up to 5 days, or freeze them for up to 3 months.