Mix water, flour, and starter in a small bowl. Cover and let sit at room temperature for about 5 hours, or until bubbly and active.
Four hours after starting the levain, combine the dough ingredients (flour and water) in a separate bowl. Mix until no dry flour remains. Cover and rest for 1 hour.
Add the levain, salt, and a splash of water to the autolyse dough. Mix thoroughly with wet hands.
Knead in the bowl for a few minutes until smooth and elastic. Cover with an airtight lid or plastic wrap.
Let the dough ferment for 4-6 hours at room temperature.