1. 1. Combine Wet Ingredients and Starter: In a large mixing bowl, whisk together the active sourdough starter, warm milk, granulated sugar, melted butter, and egg until well combined. The mixture should look slightly frothy from the starter.

2. 2. Add Dry Ingredients and Form Dough: Gradually add the salt and all-purpose flour to the wet mixture, mixing with a wooden spoon or a stand mixer with a dough hook until a shaggy dough forms. Once it comes together, turn the dough out onto a lightly floured surface.

3. 3. Knead the Dough: Knead the dough for about 5-7 minutes until it becomes smooth and elastic. It should spring back slightly when you poke it. If using a stand mixer, knead on medium speed for 5 minutes.

4. 4. First Rise (Bulk Fermentation): Lightly grease a clean bowl with a little oil. Place the dough in the bowl, turning it once to coat. Cover the bowl tightly with plastic wrap or a damp kitchen towel. Place it in the refrigerator to proof overnight, for 8 to 12 hours. The dough will slowly rise and develop flavor during this time.

5. 5. Shape the Rolls (Morning): The next morning, remove the dough from the refrigerator. Gently punch it down to release the air. Divide the dough into 12-16 equal pieces. Roll each piece into a smooth ball. Arrange the dough balls in a lightly greased 9×13 inch baking dish, leaving a little space between them as they will expand.

6. 6. Second Rise (Proofing): Cover the baking dish loosely with plastic wrap or a clean kitchen towel. Let the rolls rise in a warm spot for 1 to 2 hours, or until they are visibly puffy and have nearly doubled in size. This is a crucial step for light and airy rolls.

7. 7. Bake to Golden Perfection: Preheat your oven to 375 F (190 C) during the last 15 minutes of the second rise. Once the oven is hot and the rolls are proofed, brush the tops of the rolls with the 2 tablespoons of melted butter. Bake for 25-30 minutes, or until they are golden brown on top and cooked through.

8. 8. Serve Warm: Remove the rolls from the oven and let them cool in the pan for a few minutes before serving. They are best enjoyed warm, pulled apart right from the dish.