1. 1. Combine Wet Ingredients: In a large mixing bowl, combine the active sourdough starter (or discard), warm milk, granulated sugar, melted butter, and salt. Whisk everything together until well combined. If using instant yeast, sprinkle it over the mixture and let it sit for 5 minutes to activate.

2. 2. Add Flour and Form Dough: Gradually add the all-purpose flour to the wet ingredients, mixing with a wooden spoon or your hands until a shaggy dough forms. Once most of the flour is incorporated, 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 be slightly tacky but not overly sticky. If it’s too sticky, add a tiny bit more flour, one tablespoon at a time.

4. 4. First Rise: Place the kneaded dough in a lightly oiled bowl, turning it once to coat. Cover the bowl with plastic wrap or a clean kitchen towel and let it rise in a warm place until doubled in size. This will take about 1-2 hours with yeast, or 3-4 hours if relying solely on sourdough activity or discard.

5. 5. Shape the Rolls: Gently punch down the risen dough to release the air. Divide the dough into 12 equal pieces. Roll each piece into a smooth, tight ball. Arrange the dough balls in a greased 9×13 inch baking dish, leaving a little space between them.

6. 6. Second Rise: Cover the baking dish again and let the rolls rise in a warm spot for another 30-60 minutes, or until they look puffy and have nearly doubled in size. Towards the end of this rise, preheat your oven to 375 F (190 C).

7. 7. Egg Wash and Bake: If using, gently brush the tops of the risen rolls with the beaten egg wash. Sprinkle with flaky sea salt if desired. Bake for 18-22 minutes, or until the rolls are golden brown on top and cooked through.

8. 8. Cool and Serve: Remove the rolls from the oven and let them cool slightly in the baking dish before serving. They are best enjoyed warm.