In a microwave safe bowl, melt your butter for the dough. Whisk until it's smooth.
4 (57g) tablespoons unsalted butter
Add the whole milk, water, sourdough discard, instant yeast, egg, sugar, oil, and melted butter to the mixing bowl of your stand mixer (or a large mixing bowl if mixing by hand), and whisk until it's smooth.
¾ (175g) cup whole milk, ½ (125g) cup water, 1 egg, 2½ (30g) tablespoons granulated white sugar, 2 (30g) tablespoons avocado oil, 2¼ (7g) teaspoons instant yeast, 1 (200g) cup sourdough discard
Add the flour and salt to the wet ingredients.
4½ (550g) cups all-purpose flour, 2 (10g) teaspoons fine sea salt
If mixing with a stand mixer: Knead the dough on low for ten minutes at Speed 1-2 until the dough becomes smooth and elastic.
If mixing by hand: knead for 2-3 minutes and the dough comes together into a smooth ball.
Scrape the bowl down with a dough spatula to make sure all of the ingredients are mixed in.
Spray a straight edge container or bowl with cooking oil, and transfer the dough to the prepared bowl.
Cover the dough with plastic or a lint free cloth and allow it to rest for 30 minutes at room temperature.