1 Dissolve the yeast: In a bowl large enough to hold all the dough, sprinkle the yeast over the water and let it dissolve, about 5 minutes.
2 Warm the milk: In a saucepan over low heat, combine the milk, 3 tablespoons cut-up butter, sugar, and salt. Heat just until the butter melts and the milk feels warm to the touch of a fingertip. If the milk gets too hot, remove from the heat and let it cool to lukewarm.
3 Mix the dough: Stir the yeast mixture with a wooden spoon to mix the dissolved yeast and water. Tip in the milk mixture, still stirring, until smooth. Add 2 cups of the flour and stir again until the mixture is almost smooth, with just a few lumps.
Continue stirring in flour, 1 cup at a time, until the mixture forms a dough. It will be very soft.
4 Knead the dough: Turn the dough out onto a floured counter and knead for a few minutes until the dough is smooth, adding more flour as needed if the dough is very sticky.
5 Let the dough rise: Clean and dry the bowl, then grease lightly with a little vegetable oil. Set the dough in the bowl and turn it all around so it is oiled all over.
Cover with a clean, damp kitchen towel and set in a warm place to rise for 1 hour, or until it is puffy (it doesn’t need to double in bulk).
6 Preheat the oven to 425°F. Line 2 baking sheets with parchment paper.
7 Shape the rolls: Punch the dough down in the bowl, then transfer it to a lightly floured counter or pastry board. Knead until all the air is out.
Roll the dough to a 1/4-inch thickness. If it springs back as you try to roll it, let it rest for 5 minutes and then try again.
Use a 2 1/2-inch round biscuit or cookie cutter to stamp out rounds. Dip the cutter in flour often to avoid sticking, and stamp the rounds as close to each other as possible.
Press the back of a butter knife down the center of each round to form a crease; this is where you will fold the rolls in half. Dip the knife in flour if it starts to stick to the dough.
Brush the rounds with melted butter. Fold each round in half to make half-moon shapes and press the edges together lightly to seal them. Gather and reroll the scraps to make more rolls.
Transfer the rolls to the baking sheets, leaving 2-inches between rolls. Brush with more melted butter.
8 Bake the rolls: Transfer the baking sheets to the oven and bake for 15 to 18 minutes, rotating the sheets halfway through baking, until the rolls are puffed and golden. They’re best served warm and fresh, but leftovers will keep for a few days in an airtight container at room temperature.