Place cool water in medium bowl; add yeast and stir in flour until well mixed. Cover and let stand at room temperature 10-12 hours or until the mixture is doubled in size, light and foamy with large bubbles.
In large bowl mix flour, salt and yeast. In a medium bowl whisk together
tepid water and olive, then add to flour mixture. Add Poolish to flour mixture. With hands, mix dough until all ingredients are incorporated. Continue mixing, scraping side of bowl, for 8-10 minutes or until dough holds together and is slightly smooth (dough will be sticky, but resist urge to add more flour, dough will become less sticky as process continues). Scrape sides of bowl clean. Cover and let stand 20 minutes.
Place large baking stone in center of oven, with the broiler pan on the bottom rack. Heat to 450°F. Dough should spring back slightly, if too quick, allow to continue to rise longer. Lightly sprinkle tops with cornmeal mixture. Invert onto a transfer peel and slide onto baking stone. Repeat with other loaves.