First make the sponge. Combine all the ingredients for the sponge in a large bowl and whisk until a smooth and thick batter results. The idea is to incorporate air in the batter. Keep aside. If you're using a mixer or a processor to knead your dough, you can do this in the bowl of the machine you'll have one bowl less to wash up.

In another bowl, lightly whisk together the remaining dry ingredients except the oil and the gently sprinkle all of it over the sponge such that the sponge is completely covered by the flour mixture. Cover the bowl with cling wrap and leave this to ferment at room temperature for between one and four hours (I let it sit for 3 hours). You will find that the sponge would have bubbled up through the flour mixture in places.

When ready to knead the dough, add the oil and knead until the dough is very smooth and elastic. If the dough seems quite sticky stop the machine in between and let the dough rest for about 15 minutes. Then start kneading again, adding a little flour (not too much) if required. When the dough is of the correct consistency, if pressed with a fingertip, the dough should be springy and "jump" back. If it feels sticky, turn it out onto your counter and knead in a little extra flour.

Put the dough in a large oiled bowl, turning it well to coat with oil. Cover it and let it rise until double in volume. This should take about 1 1/2 to 2 hours. When done, turn the dough out onto a lightly floured counter and press it down gently. Fold it and shape it into square-ish shaped ball (this is an easier shape) and put it back into the bowl after re-oiling, this time for about 45 minutes. (I ended up doing this rise in the fridge for almost 3 hours because I had to step out unexpectedly!)

When this is done, turn out the dough onto a lightly floured counter and gently deflate the dough. Then shape it into a round or oblong ball and place it on a sheet lined with parchment or dusted with cornmeal or semolina. Loosely cover and let it rise until almost double in volume. This should take about an hour or so. When you gently press the dough with a fingertip, the depression should fill out slowly. If it springs back quickly, let it rise for a little longer and check again.

If you have a bread stone place it to preheat in the oven, otherwise use a baking sheet. Preheat your oven to 230C (450F).

To slash and bake the bread: With a sharp knife or singled-edged razor blade, score 1/4- to 1/2-inch-deep slashes in the top of the dough. Spray the top of the dough with a fine mist of water and quickly but gently place the dough on the baking sheet/ stone in the oven.

Bake for 15 minutes and then turn the heat down to 200C (400F) for another 30 minutes or so, until the bread is done, golden brown and sounds hollow when tapped on the bottom. Let the bread cool down completely before slicing.