Take a bowl and mix flour and salt with a whisk. Make a hole in the middle of this mixture.

In a separate bowl, mix sourdough starter and water until completely dissolved.

Pour the resulting liquid into the first bowl, in the center of the dry ingredients. Use a fork to mix until the flour is moistened. Finish mixing with slightly damp hands.

Cover the bowl with a lid or plastic wrap and let it rest at room temperature for 5 to 8 hours, until the dough begins to rise and bubble.

Take the dough with your hands and fold it over 8 times, turning it a quarter each time. Cover it and let it rest at room temperature for 30 minutes. Repeat this step 3 times.

In a cast iron casserole dish or ovenproof saucepan with a capacity of about 5 liters (20 cups) and a lid (not glass), place a circle of parchment paper the same size as the bottom.

Turn the bowl upside down onto a floured work surface to let the dough fall onto the flour. With floured hands, gently stretch the dough into a square. Bring the corners together toward the center to form a round or oval ball, depending on the size of the casserole dish.

Lightly flour. Using a pastry cutter or floured hands, quickly turn the dough over and place it in the casserole dish on the parchment paper. Adjust its shape if necessary.

Sprinkle rice flour over and around the dough. Cover. Let rest for 1 hour or until the dough has risen 1 1/2 times its volume.

Place the rack in the center of the oven.

Sprinkle the surface of the bread with rice flour. Use a razor blade to make a long incision or a few incisions on the surface of the bread. Cover again.

Place the casserole dish in the oven (turned off). Turn the oven on to 230°C and bake for 30 minutes. Remove the casserole dish from the oven and place it on a baking sheet. Remove the lid. Continue baking for 30 to 35 minutes with the baking sheet underneath. expensive.

Turn off the oven and leave the door ajar for 15 minutes. This will allow the bread to release excess moisture, preventing it from sagging.

Remove the bread from the mold, running a small spatula around the sides if necessary. Let the bread cool on a wire rack for at least 1 hour before slicing.