Preheat the oven to 425 F. Grease a 12-inch cast iron skillet with butter, set aside. If you don't have a cast iron skillet, you can also line a rimmed baking sheet with parchment paper. In a large bowl, mix together the bread flour, sugar, baking soda, garlic powder and salt.
410 grams bread flour, 25 grams sugar, 9 grams baking soda, 5 grams garlic powder, 9 grams salt
Use a box grater to shred the frozen butter. Next, add the butter, the shredded cheddar cheese, and the chopped chives to the dry ingredients. Lightly mix until the butter is dusted with flour and the cheese and chives are fully incorporated.
57 grams butter, frozen, 113 grams cheddar cheese, freshly shredded, 12 grams chives, chopped
In a separate bowl, whisk together the buttermilk, sourdough discard and egg until smooth.
310 grams buttermilk, 142 grams sourdough discard, 1 egg
Create a well in the center of the flour mixture and pour the wet ingredients into the dry ingredients.
With your hands or a wooden spoon, mix until all of the flour mixture has been fully incorporated. Be careful not to over-mix the dough!
Generously flour your workstation and your hands as this dough is quite wet and sticky.
Remove the dough from the bowl and pour it onto the floured surface. Knead a couple of times to form the dough and shape it into a round loaf.
Place the dough onto a prepared cast iron skillet.
With a floured, sharp knife, cut a deep cross onto the top of the bread.
Bake in the oven for 25-30 minutes or until the top is golden brown.
Remove the bread from the oven, rest it on a wire rack, and allow it to cool slightly before slicing. Enjoy!