In a standing electric mixer fitted with paddle attachment beat together yeast, sugar, and water and let stand 5 minutes, or until foamy.
In a bowl stir together table salt and 5 cups flour.
Stir oil into yeast mixture.
With motor on low speed, gradually add flour mixture to yeast mixture.
With dough hook knead dough 2 minutes, or until soft and slightly sticky.
Transfer dough to a floured surface and knead in enough remaining flour to form a soft but not sticky dough.
Form dough into a ball and put in an oiled large bowl, turning to coat.
Cover bowl with a kitchen towel and let dough rise in a warm place until doubled in bulk, about 45 minutes.
Transfer dough to a lightly floured surface and divide in half.
Knead thyme into one half and knead plain half 1 minute.
Form each half into an oval and invert bowl over them.
Let dough rest 5 minutes for easier rolling.
Preheat oven to 450F.
Oil two 13- by 9-inch baking pans and sprinkle each with 1 tablespoon cornmeal.
On lightly floured surface with a floured rolling pin roll out dough halves into 13- by 9-inch rectangles and fit into pans.
Cover each pan with a kitchen towel and let dough rise in a warm place until doubled in bulk, about 20 minutes.
Sprinkle plain dough with Parmesan and sprinkle both doughs with coarse salt and pepper.
With lightly oiled fingertips make indentations, about 1/2 inch deep and 1 inch apart, all over dough rectangles and bake in middle of oven 12 minutes, or until golden.