In a small saucepan over medium heat, combine bread flour, milk, and water. Keep whisking until a smooth and thick mixture forms.
Remove from the heat and let it cool to room temperature.
Brioche dough
In a glass bowl, combine warm milk, sugar, and yeast. Whisk everything. Cover with food plastic wrap and let stand for 10 minutes.
In a stand mixer, combine bread flour and salt.
On low speed with the paddle attachment, slowly mix in yeast mixture.
After combining, add tangzhong.
Lastly, combine in eggs. Keep mixing on low speed until thoroughly combined.
Change the stand mixer to the hook attachment. Start mixing on low speed and add butter in thirds.
Continue kneading on low speed for 10 minutes until dough smooth and elastic.
Transfer dough into a greased glass bowl. Cover first with a kitchen towel and after with food plastic wrap. Place a glass bowl on a heating pad for 2 hours, or until doubled in size.
Punch the dough.
Lightly flour service and place their dough. With bash n' chop cutter, divide the dough into equal 8 pieces.
Divided portions form into balls and place them on a baking sheet lined with a silicone mat.
Cover with another baking sheet and place on the heating mat. Let it rise for an hour.
Preheat oven to 375°F.
Brush buns with egg glaze.
Bake for 15-18 minutes.
Remove from the oven and brush with melted butter while hot. Sprinkle sesame or poppy seeds on top of the buns, or keep them plain.
Transfer brioche buns to the cooling wire rack to cool completely, about 1 hour.
Glaze
In a small bowl, whisk together egg and water.
Video
Notes
It is essential to let brioche buns to cool completely, for about an hour. Otherwise, the texture of the buns will be doughy.