To make the tangzhong:

In a small saucepan, combine water, whole milk, and bread flour. Whisk until smooth with no lumps.

Place the saucepan over low heat and cook, whisking constantly, for 3 to 5 minutes, or until the mixture thickens and the whisk leaves lines on the bottom of the pan.

Remove from heat and allow to cool to lukewarm.

To make the dough:

In the bowl of a stand mixer, combine the remaining dough ingredients.

Add the cooled tangzhong and mix on medium-low speed until a smooth, elastic dough forms. This may take up to 15 minutes in the stand mixer.

Shape the dough into a ball and place it in a lightly greased bowl. Cover with plastic wrap and let it rest for about 6 hours, or until puffy and just under doubled in size.

Gently deflate the dough and divide it into four equal pieces. If using a scale, each piece will weigh around 194 g, with the total dough weight being around 778 g.

Flatten each piece of dough into a 5" x 8" rectangle. Fold the short ends in toward the center, like a letter. Flatten the folded dough into 3" x 6" rectangles. Then, starting from a short end, roll each piece into a 4" log.

Place the four logs seam side down in a lightly greased or parchment-lined 9x4 pullman pan, placing them side by side.

Cover the pan and let the dough rise for about 6 hours, or until doubled in size.

After the second rise, preheat your oven to 350°F.

Brush the top of the loaf with milk, then bake for 30 to 35 minutes, or until golden brown. Use a digital thermometer to check the internal temperature, which should be at least 190°F.

Once baked, remove the loaf from the oven and let it cool in the pan until it can be safely transferred to a wire rack to cool completely.