Add flour and butter into a large bowl. Cut the butter into the flour with a pastry cutter.
Add sugar, starter, and milk or milk kefir to the flour mixture and mix until all of the flour is incorporated.
Next, add the shredded cheese and stretch and fold the dough to get the cheese mixed in.
Cover with plastic wrap and allow to ferment on the counter for 16-24 hours, or overnight.
Flour your counter and place dough on counter. In a small bowl, mix salt, baking soda, and baking powder together. Then sprinkle that mixture on top of the dough. Knead the mixture into the dough until well combined. If desired, add chives at this point and knead into the dough.
Butter 9x13 inch pan, and spread the dough out evenly. Using a bench scraper or knife, cut the dough into 1x1 inch squares. Let the dough rest for 15 minutes on the counter.
Heat the oven to 425 degrees, and bake for 25-30 minutes.
Fresh out of the oven, brush the tops generously with melted butter. Enjoy!