1. 1. Combine Wet Ingredients and Discard: In a large mixing bowl, whisk together the warm milk, sourdough discard, sugar, and salt until well combined. The mixture might look a little lumpy from the discard, which is perfectly fine.

2. 2. Add Yeast and Flour: Sprinkle the instant yeast over the wet ingredients, then gradually add the all-purpose flour, mixing with a wooden spoon or a sturdy spatula until a shaggy, sticky dough forms. Avoid overmixing; just ensure all the flour is incorporated.

3. 3. Incorporate Melted Butter: Pour the melted butter over the dough and mix until it’s fully absorbed. The dough will still be sticky, but the butter helps to enrich it and add flavor.

4. 4. First Rise: Cover the bowl with plastic wrap or a clean kitchen towel and let it rise in a warm place for 2-4 hours, or until doubled in size. The dough should look bubbly and airy. If your kitchen is cool, this might take longer.

5. 5. Shape the Muffins: Once risen, gently deflate the dough. Lightly flour a clean work surface and sprinkle it generously with cornmeal. Turn the dough out onto the cornmeal. Pat the dough gently into a rectangle about 3/4 to 1 inch thick. Use a 3-inch round cutter (or a wide-mouth jar rim) to cut out circles. Re-roll scraps gently and cut more muffins until all dough is used.

6. 6. Second Rise: Transfer the cut muffins to a baking sheet lined with parchment paper and dusted with cornmeal. Leave about an inch between each muffin. Cover loosely with plastic wrap or a kitchen towel and let them rise again for 30-60 minutes, or until visibly puffy.

7. 7. Cook on the Griddle: Heat a lightly greased griddle or a large cast-iron skillet over medium-low heat. The key is low and slow cooking to ensure they cook through without burning. Place a few muffins on the griddle, leaving space between them.

8. 8. Flip and Finish: Cook for 6-8 minutes per side, or until golden brown and cooked through. They should sound hollow when tapped. You might need to adjust the heat to prevent them from browning too quickly. Transfer cooked muffins to a wire rack to cool slightly before serving.