Line 2 baking sheets with parchment or wax paper.
In a bowl dissolve the yeast in the water. Add 3 tablespoons of the olive oil, the rosemary, garlic, flour, and salt. Mix and knead well by hand until you have a smooth ball of dough.
Spread the cornmeal on a flat surface. Place the dough on the cornmeal and cover with a warm, damp dish towel. Allow the dough to rise until double the size, for about 50 minutes.
About 15 minutes before baking, preheat the oven to 400ºF.
With a rolling pin, flatten the dough into a round and cut it into 6 equal wedges. Flatten each wedge with your fingers, pounding it out very thin. (Don’t worry about holes—they add character.) Spread on the baking sheets and bake until golden brown, for a bout 10 minutes. Brush each piece of flatbread with 1/2 teaspoon of the remaining 1 tablespoon olive oil, and sprinkle lightly with the kosher salt. Serve warm.
Yield: 6 wedges