Cook on medium until it becomes thick. Then set it aside until ready for use in step 3.
Prepare the dough in a mixer
Mix yeast, lukewarm milk and sugar in a bowl;then let it sit for 5 minutes.
Add bread flour, salt, egg, egg yolk and butter to the mixer. Mix and knead for about 1-2 minutes. Then add the tangzhong (from step 1) to the dough in the mixer. Knead for 5 minutes on low (speed 2).
Shape the flour into a ball and place it into a lightly greased bowl. Cover with a towel for 1-2 hours or until it doubles in size.*
Punch the dough and divide it into 5 equal parts. Shape each dough part into a nice round shape. Let them sit for another hour or until they double in size. *
Preheat the oven to 375° degrees.
Prepare the buns for the oven: Brush the egg wash over them. Then sprinkle the “everything” seasoning on top of the buns.
Place buns in the oven and cook for 16-18 minutes or until they are golden brown.
Notes
*Tip Step 4 & 5: I put the dough next to my window so the sunlight form outside can help it rise.