Sponge making: Combine flour, yeast, and water in a bowl. Knead the ingredients with your hand and try to form a small ball. After that, with a cling wrap cover the bowl and let it sit for 12-15 hours. Remember to let it rise at room temperature. After 12-15 hours the dough should be bubbling and loose.
Dough making: Sift in flour and yeast. Add water and starter, and with your spatula stir the mixture until it forms a ball of dough. Cover with plastic wrap, and let rest for 20 minutes.
Transfer dough onto an unfloured table top. Sprinkle with salt, and drizzle with oil. To incorporate oil into bread, use one hand to stretch half of the dough away from you, at the same time, your other hand should be stretching the other half towards you. Fold it in half, and repeat until oil has been completely incorporated (dough will no longer have a sheen to it and there should be no oil on the work surface).
Kneading: Gather dough, lifting it above the work surface. Hold one end of the dough close to you while you cast the other end in front of you, onto the surface. Pull the ends of the dough towards you with your hands, stretching it gently, then fold the dough in half on top of itself. Repeat: Lift, cast, stretch, and fold. Knead the dough until it is smooth, supple, and elastic, 8 to 10 minutes. Use a dough scraper to clean the surface as needed, adding the scraps to the dough. (Dough will be very sticky, but avoid adding more flour until the end, only when it is necessary, add a very small amount. Also, add the flour to your fingers, not the dough.) Finally, mold the dough into a ball.
Place dough in a lightly oiled bowl and cover with oiled plastic wrap. Let it rise at cool room temperature for 45 minutes.
Gently turn dough onto a lightly floured surface. (Do not punch dough to deflate.) Fold into thirds, as you would for a business letter. Then fold it in half diagonally. Place it back into a bowl, cover, and let rise at cool room temperature until it has almost doubled, for at least 75 minutes.
Gently turn dough onto a lightly floured surface. Using a dough scraper or a knife, divide dough into 2 equal portions. Cover it with oiled plastic wrap and let rest for 20 minutes.
On a lightly floured surface, spread each portion of dough into a rectangle that's roughly 6 by 4 inches. (Be careful not to deflate bubbles.) Fold dough into thirds again, as you would a business letter, pressing seams with lightly floured fingers. Place dough, seam side down, on a generously floured linen towel or a baking sheet lined with floured parchment. Cover loosely with an oiled plastic wrap, use a floured finger to press into the side leaving a slight indentation, and let rise at cool room temperature until it has almost doubled for 40 to 50 minutes.
Place a skillet on the oven rack adjusted to the lowest position and a baking stone on the middle oven rack. Preheat the oven to 500 degrees. If you are using a linen towel, gently transfer dough to a parchment-lined baking sheet. Just before baking, stretch each portion into a 10 by 4-inch rectangle. Immediately dimple the entire surface with lightly floured fingers. Pour 1/2 cup hot water into the skillet in the oven. Slide bread and parchment on the baking stone.
Immediately reduce the oven to 450 degrees. Bake, rotating once, until bread is golden brown, sounds hollow when the bottom is thumped, and the interior registers 205 degrees on an instant-read thermometer which will be about 15 to 20 minutes. Let cool on wire racks. There you have it! An artsy looking artisan bread!
