TANGZHONG

1. Combine the milk and bread flour in a medium saucepan. Place over medium heat and cook, stirring continuously, until the mixture thickens into a paste. Remove from heat and transfer to a medium bowl.

DINNER ROLL DOUGH

1. Add the cold milk to the tangzhong and mix to combine. Check with your finger that it is not too hot (it should be cool or lukewarm). Add the flour, milk powder, sugar, yeast, and salt. Bring together to form a shaggy dough, then cover with a tea towel or a plate and leave to sit for 5 minutes. This step helps the flour to hydrate a little and makes the dough a little easier to work with.
2. Add the butter to the bowl and mix to bring together. Turn out the dough onto a clean work surface, and using your hands and a bench scraper when needed, knead the dough for about 10 minutes. It will be super sloppy at first and you may need to scrape the bench a few times to bring the dough together, but keep kneading - it will come together. Knead until a soft, smooth dough forms, that when pressed lightly with a finger, leaves an indentation that starts to spring back.
3. Shape the dough into a ball and transfer to a buttered bowl. Cover the bowl with plastic wrap and leave in a warm spot until doubled in size, 1 to 1 ½ hours.
4. Grease and line an 8” (20cm) square pan. Turn the dough out onto a lightly floured surface and divide into 9 pieces, each weighing about 65g each. Working with one piece of dough at a time, flatten out the piece of dough, then tuck up into a ball, then turn the ball seam side down and roll into a tight ball by cupping your hand to create a 'claw' shape, using the tension from the counter to roll the dough tightly. Place to the side and cover lightly with plastic wrap. Repeat with the remaining pieces of dough, grouping the balls together on your counter with a little space between them so they don't touch.
5. Leave the buns to rest for 10 minutes, then give them a quick roll to tighten them back up. Arrange them evenly in the pan. Alternatively you can space them out individually on a sheet pan.
6. Cover the buns either with a lid, or some lightly greased plastic wrap, or place a second sheet pan upside down over the top to act as a lid. Leave the buns to rise again for about 45 minutes to an hour. You want them to puff up and double in size, and when you press lightly on one, it should leave a small indentation that doesn't quite spring back. Remember that rising time depends on your environment so go by how the dough is looking, rather than a rising time.
7. While the dough is rising, preheat the oven to 350°f / 180°c. Brush the rolls with the egg wash (if you don't want to use egg wash you can use milk). Bake for 18-20 minutes, until golden brown on top. Remove from the oven and leave to cool slightly in the pan before transfer to a wire rack and allowing to cool completely.
8. Store leftovers in an airtight container at room temperature. Refresh before eating