Combine bread flour and water/milk in a small pot. Cook over medium heat, stirring constantly, until it has a pudding-like consistency.
Remove from heat and let cool completely before using.
Main Bread Dough
Butter or oil a large mixing bowl, set aside.
Place milk, egg, TangZhong, bread flour, caster sugar, milk powder and salt in another clean and dry mixing bowl. Fit the mixer with a dough hook and run on low (Speed 1 on Kenwood Chef Sense) until a loose dough is formed. Add in the yeast and knead until a dough is formed, scrapping down the sides if necessary.
Add in the unsalted butter and knead for 15 minutes until the dough is soft and no longer sticky.
Lightly dust the table top with bread flour. Transfer the dough onto the floured table top and knead by hand for another 5 minutes, dusting with more flour if needed (but not too much). Pinch a piece of dough a test if it's ready - the dough is ready when it can be stretched into a thin membrane and a hole poked in the center is smooth and not an irregular tear-off.
Shape the dough into a ball and place in the buttered/oiled mixing bowl. Cover with clingwrap and set aside in a warm and draft-free area to rise for 1 to 2 hours, until double in size. (See Naggy 3)
Shaping
Lightly dust the table top with bread flour again. Turn the dough out again onto the floured table top and knead for 2 minutes.
Burger Buns: Divide the dough into 8 to 9 equal pieces (about 80 grams each) and roll each piece of dough into a ball. Flatten slightly and place on a baking sheet. Cover and let rise for 1 hour.
Dinner Rolls: Lightly grease a 9x9-inch or 10x10-inch baking dish. Divide the dough into 12 equal pieces (about 60 grams each) and roll each piece into a ball. Place them into the greased baking dish, cover and let rise for 1 hour.
Baking
Preheat oven to 180C / 355F (not fan-assisted).
Burger Buns: Brush the top with milk (you can use egg or cream) and sprinkle sesame seeds on top.
Dinner Rolls: Brush the top with milk (or egg or cream).
Bake for 20 to 25 minutes until the top is golden-brown. Remove the buns/rolls from the oven and set on a wire rack to cool before using.
NOTES
1) For first-timers: If this is the first time you are making the bread, add only 80 grams of milk instead of 125 grams. This is because different brands of bread flour absorbs liquid differently. Add more milk after mixing in the butter if the dough is dry.2) Scalding the milk: Heat the milk to a simmer, stirring frequently to prevent a skin from forming on the top, then let cool until it's warm or at room temperature before using. Some milk has a type of protein which inhibits yeast rise. Hence it's best to heat the milk to denature (sort of kill) the protein before using.3) Overnight: You can let the dough proof overnight in the refrigerator. Just wrap the bowl with a clingwrap and stash it in the refrigerator.4) The bread is best on the day it's made, but you can bake the bread up to a day in advance before using.