In a large bowl, combine flour, starter, salt, sugar, butter, egg, yeast, and water until a shaggy dough forms. 

Turn dough out onto a generously floured surface and knead until smooth, adding a bit more flour if needed. Dough will be quite sticky. 

Spray a deep bowl with cooking spray and transfer dough to bowl. Cover with plastic wrap and let rise until doubled, about 3 hours (if omitting the instant yeast, this rise time will be substantially longer). 

Lightly sprinkle countertop with flour and cornmeal. Roll dough out until about 3/4-inch thick. Using a biscuit cutter, cut dough into 8 circles, about 3-inches in diameter. 

Transfer dough rounds to a cornmeal covered baking sheet. Cover and rise for 1 hour (longer if not using instant yeast) until puffed up. Heat a nonstick skillet over medium-low heat. Do not oil the skillet. Place 2 or 3 dough rounds onto the hot skillet with the cornmeal side up, cooking until golden brown, about 4 minutes. Flip over and cook 4 minutes more. Adjust temperature as needed to prevent them from browning too quickly. 

Repeat with remaining dough.

Let cool slightly before slicing and serving.