Knead the sourdough starter, flour, olive oil, any herbs or spices you’re using, and 1/4 teaspoon fine sea salt into a smooth ball. Wrap tightly in plastic wrap and place in the fridge for 30 minutes or overnight. This will make it easier to roll out.
When you’re ready to bake, heat the oven to 350°F. Place the racks on the top and bottom third of the oven.
Divide the dough into four equal parts. Lightly flour and place between two sheets of parchment paper and roll out, as thin as you can. Alternately, lightly dust with flour and run through a pasta machine, dialing down the thinness as you roll. I usually roll our crackers out to 4 or 5 which was plenty thin and crispy.
Place the crackers on a parchment paper lined baking sheet and lightly brush with water and sprinkle with flaky sea salt, if desired.
Bake for 12-15 minutes, rotating from top to bottom, front to back, until crispy, golden brown, and baked through. Let cool completely before cracking into irregular shaped pieces and enjoying!