Preheat your oven 425 degrees and place parchment paper on a baking pan.
Put all your dried ingredients together in a bowl and whisk them together.
With a butter cutter, cut the butter into the flour mixture.
Cut the butter in until the flour looks like it has a bunch of small clumps.
Mix in your sourdough starter and your milk and mix well. I mix it with my hand.
The dough may seem raggedy at first, but keep mixing in the flour. It gets wetter as you go.
Fold the dough, and then fold it 4 more times moving the bowl a quarter circle each time.
Press the dough out on a cutting board into a nice rectangle. Use a cookie cutter or cup to cut out the biscuits.
Once you cut out the first few biscuits, mash the dough back together and continue doing this until no more dough remains.
Put the biscuits on a cookie sheet and cook for about 15 minutes.
Once you pull out the biscuits make sure to butter them generously.
Enjoy!