Mix together the yeast, sugar and water in a bowl and let it stand about 5-10 minutes until the yeast turns frothy.
Add the sourdough starter and then the flour, one cup at a time, mixing with the dough hook attachment of a stand mixer or with your hand. Once you have a thick but somewhat liquid mixture, add the salt and continue to mix in the flour.
Use just as much flour as is needed to get a smooth but not sticky dough. You want a pliable dough that's not as stiff as the dough you'd make for a chapati.
Knead the dough for 8 minutes on medium-low speed or by hand. Turn it out onto a flat surface, form into a smooth ball with your hands, and place in an oiled bowl, turning over once to coat the top with oil.
Cover the dough with a kitchen towel or plastic wrap and set aside in a warm place to double, about an hour.
Once the dough has doubled, punch out the gases and divide into two. Shape each portion into a round loaf, tucking any seams underneath the loaf.
Lightly oil a baking sheet and scatter some sooji rava or cornmeal on it.
Place the loaves, about four inches apart, on the baking sheet. Dust the tops with some flour, then cover loosely with a kitchen towel and let the loaves rise for 2 hours.
Preheat the oven to 400 degrees Fahrenheit.
Just before putting the loaves in the oven, use a very sharp, preferably serrated knife to score the tops of the loaves. I scored them in a crosshatch pattern but you could do diagonal slashes as well.
Place the loaves in the oven and bake for 30 minutes or until the bottoms sound hollow when tapped with your fingertips.
Remove the baking sheet to a rack and cool for 10 minutes, then remove the loaves from the sheet and continue cooling them on the rack.
Recipe by Holy Cow! at http://holycowvegan.net/2013/11/whole-wheat-bread.html