Melt the butter and set aside to cool. In the bowl of a stand mixer, whisk together the yeast, salt, and all purpose flour.
2 1/4 tsp instant yeast, 6 grams salt, 325 grams all purpose flour
Warm the milk to 95 degrees F. Add the milk, cooled butter, egg, and sourdough discard to the dough.
40 grams honey, 115 grams warm milk, 1 egg, 65 grams melted butter, 150 grams sourdough discard
Using the dough hook, turn the mixer on low speed and mix to incorporate the dough. Knead the dough on low speed using the dough hook for 7-8 minutes. The dough will be sticky and wet! This is normal. It will feel like extra soft, damp playdough. Form the dough into a loose ball using your hands, then cover with plastic wrap and let it bulk rise until double in size, about 80-90 minutes.
Turn the dough out onto a lightly floured surface. Weigh the dough on your scale and divide it into nine equal pieces, about 70-75 grams each. Fold each piece of dough over on itself to form a ball shape. Cup the dough with the sides of your hands and rotate it on the table to firm up the shape.
Place each dough ball into the pan in rows of three. Cover and let the dough rise for 30-40 minutes for the second rise, until puffed up.
Preheat the oven to 350 degrees F, you want it nice and hot before baking.
Optional: Create an egg wash by mixing one egg yolk with two tablespoons of water. Brush the mixture over the tops of the rolls with a pastry brush.
Bake for 20-22 minutes or until the rolls are golden brown on the top. Let cool, than slather in butter and enjoy!