Dissolve yeast in 2 1/2 cups warm water in a large bowl. Let stand until creamy, about 10 minutes.
Meanwhile, lightly grease a large bowl. Lightly grease two baking sheets and dust with cornmeal. Set aside.
Add 4 cups flour, oil, and salt to yeast mixture; beat with an electric mixer until well combined. Add remaining flour, 1/2 cup at a time, beating on medium speed until well combined after each addition.
When dough has pulled together, turn it out onto a lightly floured surface and knead until smooth and elastic, about 6 minutes.
Place dough into the greased bowl and turn until coated. Cover with a damp cloth and let rise in a warm place until doubled in volume, about 40 minutes.
Punch dough down and divide into 8 equal portions. Shape each portion into a 4-inch round loaf; place four loaves onto each prepared baking sheet. Cover and let rise in a warm place until doubled in volume, about 35 minutes.
Preheat the oven to 400 degrees F (200 degrees C).
Whisk egg white and 1 tablespoon water together in a small bowl. Brush 1/2 of the egg wash over loaves.
Bake in the preheated oven for 15 minutes. Brush loaves again with remaining egg wash and continue to bake until golden brown, 10 to 15 more minutes. Cool on wire racks.
Make bread bowls by cutting a 1/2-inch thick slice from the top of each loaf. Scoop out bread in the center, leaving a 3/4-inch thick shell. Fill bread bowls with hot soup and serve immediately.
