1. In a small bowl, sprinkle the yeast over the warm water and let stand until foamy, 5 to 8 minutes.
2. In a medium bowl, blend the flour with the cornmeal, 1/2 teaspoon of salt and the chives. Add the yeast mixture and the 3 tablespoons of olive oil and stir until a firm dough forms. Cover the bowl with plastic wrap and let the dough rise at warm room temperature until doubled in bulk, about 30 minutes.
3. Preheat the oven to 450°. Lightly oil 2 large baking sheets. Punch the dough down and divide it in half. On a lightly floured surface, roll out 1 piece of dough to a 12-by-10-inch rectangle. Cut the rectangle lengthwise into 2-inch-wide strips. Transfer the strips to a baking sheet. Repeat with the remaining dough. Set the strips aside until they puff and start to rise, about 8 minutes. Sprinkle lightly with kosher salt. Bake for about 8 minutes, or until browned around the edges and crisp. Transfer the breads to a rack and let them cool completely.
Make Ahead: The flat breads can be stored in an airtight container overnight. Recrisp them in a 350° oven for 3 to 5 minutes before serving.