Knead the dough. Add all ingredients to a stand mixer fitted with a dough hook, a bread machine, or a large mixing bowl if kneading by hand. Then, knead until the dough is smooth and stretchy, about 8-10 minutes. To see if it's kneaded enough, try the "windowpane test": stretch a small piece of dough thin enough to let some light through without it breaking. The dough should be smooth and slightly sticky to the touch but should clear the sides and bottom of the bowl. If using a bread machine, allow the kneading cycle to finish.
First rise. Place the dough in a lightly oiled large bowl and cover with a damp cloth or plastic wrap. Let it rise in a warm place for 1 hour, or until it has doubled in size and is very puffy.
Rest. After the first rise, gently deflate the dough and divide it into 8 equal pieces. For best results, use a kitchen scale to make sure you get even portions. Loosely shape each piece into a log. Then, cover the logs with plastic wrap and let them rest at room temperature for about 10 minutes. This rest period will make the dough easier to shape.
Shape. Prepare a baking sheet by lining it with parchment paper and dusting it with cornmeal. To shape the rolls, gently stretch each log into an oval roll. Pull down the bottoms of the dough to smooth out the tops and pinch the ends underneath to create a smooth, seam-free surface. Place the shaped rolls on the prepared baking sheet, leaving enough space between them for the second rise.
Second rise. Brush the tops of the rolls with melted butter using a pastry brush. Cover them with heavily greased plastic wrap to prevent sticking and allow them to rise in a warm place for about 45 minutes, or until very puffy. Towards the end of the rising time, preheat your oven to 425°F. Place a rimmed metal baking sheet on a lower rack in the oven to preheat as well.
Bake with steam. When the oven is hot, pour 1 cup of water onto the preheated metal baking sheet to create steam. Immediately place the rolls on the middle rack of the oven. Bake for 15-19 minutes, or until the rolls are golden brown and sound hollow when tapped on the bottom.
Cool and serve. Remove the rolls from the oven and cool on a wire rack. Let them cool completely before slicing for sandwiches. These rolls are best enjoyed within 2 days or can be frozen for later use.