Prepare Tang Zhong by mixing Blue Jacket Bread Flour and water in a pot. Cook in medium to low heat till paste like. Set aside to cool or leave in fridge.
 

Mix yeast mixture (B) and set aside for a few minutes to ferment and add egg
 

Combine dough ingredient (C), Tang Zhong and yeast mixture. Mix and knead for 5-7min.
 

Cover and set aside for 1st proofing for 1 hour or dough double in size.
 

Remove dough and knead for a few minutes. Shape into balls or loaf.
 

Set aside for 2nd proofing, 30-45min. Brush dough with egg yolk.
 

Bake 180 degree for 25-30min.