Make the rolls. In the bowl of a mixer stand, whisk the warm water and yeast until the yeast is fully dissolved, let sit for 5 minutes.
Add the milk and whisk to combine.
Add the flour, salt and sugar and, using the hook attachment, mix until the bulk of the flour has been incorporated.
Add the butter, a little at a time, and mix until it is fully incorporated into the dough, then, with the mixer on medium-low, knead until the dough is smooth, for 8 to 10 minutes.
Cover with plastic wrap and let rise in a warm place until doubled in size, approximately 1 hour.
Punch down the dough, fold it over itself a couple times, then cover with plastic wrap and let rise in a warm place until doubled in size, approximately 1 hour.
Meanwhile, grease (7) 5-inch pans generously with butter and preheat the oven to 375-degrees.
Using a kitchen scale, portion the dough into 39- to 41-gram pieces.
On a clean work surface, working one at a time, using your dominant hand, press down on the dough with your palm while making small circular motions until the dough is the same consistency, then begin to cup your hand, still moving in a circular motion, and begin to pull away from the dough to form a tight ball.
Place six balls into each pan, lightly cover with a clean tea towel or plastic wrap, and allow the dough to proof once again until the rolls have risen enough to fill the pan and are springy to the touch, approximately 15 minutes.
Bake until golden brown, and an instant-read thermometer reaches 190-degrees when inserted into the center roll, for about 25 minutes.
Using a pastry brush, generously coat the tops of the rolls with butter and add a generous sprinkling of flaky sea salt before serving. Serve with additional salted butter