Weigh your flour; or measure it by gently spooning it into a cup, then sweeping off any excess. Combine the tangzhong with the remaining dough ingredients, then mix and knead — by mixer or bread machine — until a smooth, elastic dough forms; this could take almost 15 minutes in a stand mixer.
Shape the dough into a ball, and let it rest in a lightly greased bowl, covered, for 1 to 1½ hours, until puffy but not necessarily doubled in bulk.
Gently deflate the dough and divide it into four equal pieces; if you have a scale each piece will weigh between 170g and 175g.
Flatten each piece of dough into a 5" x 8" rectangle, then fold the short ends in towards one another like a letter. Flatten the folded pieces into rectangles again (this time about 3" x 6") and, starting with a short end, roll them each into a 4" log.
Place the logs in a row of four — seam side down and side by side — in a lightly greased 9" x 5" loaf pan.
Cover the loaf and allow it to rest/rise for 40 to 50 minutes, until puffy.
Toward the end of the rising time, preheat the oven to 350°F.