To proof the yeast, combine 1/2 cup (120 ml) warm water with the yeast. Stir slowly to combine. Set aside for 5 minutes. Place flour and salt, optional into the Vitamix DRY BLADE container and secure lid. Start the blender on its lowest speed and slowly increase speed to Variable 6. Blend until a hole forms in the center of the flour mixture, about 5 seconds. Select Variable 3. Start the blender and remove the lid plug. Slowly add yeast mixture and remaining 1/2 cup warm water, a little at a time, just until incorporated, through the lid plug opening. Stop machine and replace lid plug. Select Variable 10. Pulse two times. Stop machine and remove lid. While dough rests, grease a medium-size mixing bowl with the olive oil and sprinkle the cornmeal on a baking sheet. Use a wet nylon spatula to scrape the sides of the container, pulling the dough away from the container sides and into the center of the mixture. Replace lid. Select Variable 10. Pulse five times. Add additional water, 1 Tablespoon at a time, only if dough seems exceptionally dry. Repeat process five times, scraping the sides of the container until the dough binds together into a soft, elastic mixture. To aid in removing the dough from the container, pulse five times (this lifts the dough up and away from the blades) and slowly invert the container over the prepared bowl, using a wet spatula to remove any remaining dough. Turn dough to coat well. Cover with plastic wrap and allow rising until almost triple in size, 45 minutes to 1 hour. Lightly punch down dough and place on a floured work surface, adding additional flour as needed to make workable but still soft dough. Roll into a 12-inch x 6-inch (30 cm x 15 cm) rectangle with a floured rolling pin. Roll from the long end down, pinching the seams together and using water to seal. Place dough, seam side down, on prepared baking sheet. Cover with a clean, dry kitchen towel and allow the dough to rise until it doubles in size, about 45 minutes to 1 hour. Brush top of loaf with egg mixture and make three to four diagonal slits about ¼ inch deep on the top of the loaf using a sharp, serrated knife. Bake in a heated 425°F (220°C) oven for 30 to 40 minutes or until bread is well browned and reaches an internal temperature of 190°F (88°C) when tested with an instant read thermometer. Cool on wire rack 10 minutes, then carefully remove from the baking sheet and allow to cool completely before slicing.