1. Whisk the starter: 1/2 cup warm water, 1/2 cup flour, 1/2 teaspoon yeast. Cover and refrigerate 8 hours to overnight.

2. In a mixing bowl combine 1 package yeast and 2 teaspoons sugar with 3/4 cup warm water. Rest 15 minutes until foamy.

3. Add 3 tablespoons vegetable shortening and 2 teaspoons salt. Mix in 1 cup flour, then add the starter.

4. Add the remaining flour, holding back up to 1/2 cup. Mix until a shaggy, sticky dough forms.

5. Knead on a lightly floured surface to a soft, supple ball, adding just enough of the held-back flour so the surface is slightly tacky.

6. Place in a lightly oiled bowl, coat the dough, cover with a damp towel, and let rise warm until doubled, about 2 hours.

7. Line two rimmed baking sheets with parchment and sprinkle with cornmeal.

8. Press dough into a rectangle, divide in half, and shape each into a 12-inch-long, 1/2-inch-thick rectangle. Roll tightly from the long side into two skinny loaves. Lightly flatten tops and dust with flour.

9. Set loaves on the prepared sheets. Cover with a light dry towel and rise until doubled, 1 1/2 to 2 hours.

10. Preheat oven to 400°F (200°C). Slash a 1/4-inch-deep slit down each loaf and lightly mist with water.

11. Bake with one pan on the lower rack and one on the upper rack for 10 minutes. Switch positions and bake 10 to 15 minutes more until golden brown.

12. Transfer to a rack and cool to room temperature before slicing.