In a bowl, combine the sourdough starter and warm milk.
Add sugar and mix well.
In a separate bowl, mix flour, salt, and baking soda.
Gradually add the dry ingredients to the wet mixture.
Stir until a soft dough forms.
Knead the dough on a floured surface for about 5 minutes.
Shape the dough into a ball and place it in a greased bowl.
Cover with a damp cloth and let it rise for 1-2 hours.
Once risen, divide the dough into equal portions.
Flatten each portion slightly and dust with cornmeal.
Heat a skillet over medium heat and cook each muffin for 7-8 minutes on each side.