Dissolve yeast and sugar in 1/2 cup warm water. Set aside. In a mixing bowl mix 1-1/2 tbsp warm water, baking soda, milk, salt and 1 cup of the flour. Beat until smooth. Add yeast mixture and remaining flour. Grease 2 pie pans and sprinkle lightly with cornmeal. Pour 1/2 of the dough into each pan. Brush lightly with olive oil, cover with a towel and let rise in a draft-free spot for 1 hour. After rising, brush with olive oil once more, then 20 minutes in a 375°F oven. Let cool on a rack before slicing.