The night before baking the bread, feed your sourdough starter. Use 2 tbsp of starter and feed it 3/4 cup (90 grams) white unbleached flour and 6 tablespoons (90 grams) water. Cover it and let it sit on the counter overnight.

The next morning, the sourdough starter should have at least doubled in height. In a large glass bowl, stir together the flour, water, 3/4 cup starter, and salt. I've found that rather than stirring it with a wooden spoon, a sturdy rubber spatula works even better: with the spatula, scrape the dough away from the walls of the bowl and fold it in on itself. Mix the entire loaf this way, until the dough is uniform in color and texture. It should only take a minute or two. Dough will be very wet.

Cover the bowl and let it sit for at least 5 hours or up to 10. I let it rise in my oven with the light on (oven is OFF) so it stays nice and warm. This helps it rise faster too. If you can, put a piece of tape or a post-it note on oven controls so no one accidentally turns it on (ask me how I learned this trick).

Layout two large baking sheets and drizzle them generously with oil. Use your hands to spread the oil evenly on the pan so the dough doesn't stick. With your oiled hands and a thick pancake turner, divide the dough in half as best you can (it will be wet), and gently pour each half onto the baking sheet.

Use your hands to gently spread the dough out on the baking sheet. Don't rip the dough or smash it too much. The best word I can think to use is squoosh. Squoosh the dough gently with the tips of your fingers until it stretches across the whole baking sheet.

Put the baking sheets in your oven (you don't need to cover them if they are rising in the oven) with the light on and the oven OFF. Let them rise for about 1 hour, maybe 2. They may not puff up a lot, but you want them to look loose and spongy by the end.

Take the baking sheets out of the oven and place them on the stove top. Remove the tape or post-it note on the oven controls, and preheat the oven to 450 F. Set a timer for 20 minutes.

After 20 minutes, check on your flat bread loaves. They should be visibly poofy, but not overly so. If you think they need another 20 minutes, feel free to give them that. (Optional: just before baking, drizzle the tops of the loaves with olive oil and kosher salt.)

Bake them on separate racks of the oven for 15 minutes. Then switch racks and turn the baking sheets so the parts of the loaves that were in the back of the oven are now facing the front. This will help them bake evenly. Bake for another 10 minutes, until the crust is golden brown.

Remove flatbread from the oven and let it cool for at least 20 minutes. Slice and serve. You can also cut it in half crosswise and make flatbread sandwiches.