Add all the ingredients to the mixing bowl with the bread hook attached, mix on slow speed for 5 minutes, and incorporate all the ingredients. Then turn the mixer to medium speed for another 2 minutes. Mix until the dough becomes elastic and flexible. To check it, pull out a small piece, round it up in your palm, then slowly stretch it out till it passes the windowpane test (stop at 60-70% gluten development). Then round it up and let it rest in the refrigerator overnight.
2 cups bread flour, 1 tsp salt, 3 tbsp granulated sugar, ¼ oz dried yeast, 4 ½ oz milk, 2 tbsp unsalted butter