Sourdough Biscuits

Preheat oven to 230C. Lightly butter the bottom of a 10-inch cast iron skillet. In a bowl, whisk together flour and baking powder, baking soda, and salt. If it's particularly warm in your kitchen you can chill the bowl and flour mixture before continuing. Add cold cubed butter and cut in with a pastry blender or two knives until butter forms pea-sized pieces coated in flour. Add sourdough starter and 2 tablespoons of milk and mix with a fork until dough starts to come together in a shaggy dough. If dough seems particularly dry (this will depend on the maturity/hydration of your starter), you can add more milk as needed. I found about 1/4 cup of milk was just about right. Knead and fold the dough in the bowl a few times to incorporate any remaining dry crumbs (just until it comes together, you don't want to overwork it). Turn dough out onto a work surface. Press into a circle about 1 inch thick. Cut into rounds using a 2¼ to 2½-inch circle cutter or biscuit cutter. Dip your cutter in flour then press it straight down into the dough and lift back up without twisting (twisting will 'seal' the layers and prevent the biscuit from rising properly). Evenly space in prepared cast iron skillet. You can press the scraps of dough together once more and cut a few more biscuits from this, just know these re-rolled biscuits won't rise quite as high. Brush tops of biscuits with milk. Bake for about 15 minutes or until tops of biscuits just start to turn golden brown. Remove from oven and immediately brush with melted butter; serve warm.