You start these the night before and finish them up in the morning.
Combine starter, milk and 4 cups of flour in a bowl. Stir and cover. Leave on counter all night.
In the morning, add 1 cup of flour, baking soda, brown sugar and salt in a small bowl. Mix.
Add flour mixture to starter mix and mix well. Continue to add flour until you have a nice soft dough. The amount of flour will different each time because your sourdough starter may be more or less liquidity so adjust the flour as necessary. You want a soft dough but NOT stiff.
Knead for 3 minutes
On a floured surface, roll out your dough to 1/2" thick. Using a biscuit cutter or glass cup, cut 3-4" rounds and place on a lightly cornmeal dusted cookie sheet.
Allow muffins to rest for 45 minutes before cooking.
On a medium-hot skillet (ungreased), place muffins and allow to cook until a dark golden brown on one side. Flip and cook the second side. It should take 8-10 minutes per side. IF the skillet is too hot, they will brown too fast and not cook completely.
Split with a fork and toast. Enjoy!