Milk(or a combination of condensed milk and water)
Half Beaten Egg
Sesame seeds
Instructions
For the Tangzhong (water roux):
Start with the water roux: in a small pan, combine water and flour then whisk.Place it over low heat on the stove and keep whisking with a spatula or a tiny silicon whisk, until you get a thick gel-consistency mixture (and it reaches 65°C/150°F)
Pour the water roux on a plate, cover with plastic wrap and let it cool at room temperature.
For the hamburger buns:
(I usually use a bread machine, but if you have a stand mixer that's even better. You can make them by hand too.)
Put whole wheat flour, sugar, salt into the machine and program it for "dough", press Start. Add dry yeast and 120 gr of warm water (ideally at 35-40° C / 95°-104°F).
Gradually add the beaten egg, condensed milk, Tangzhong and let incorporate.
Add the oil + water and let knead for 15/20 minutes.
Place the dough into a greased bowl, cover with plastic wrap and let it rise for 50 minutes in a warm place (in Summer, you'll probably need less time).
After the dough has doubled in size, press it - gently! - to degas it.
Divide it into 8 pieces (about 75 gr each) and roll them into balls. Cover and let them rise for 50 minutes.
Preheat your oven at 180°C (350°F).
Combine milk and egg, brush the buns and sprinkle some sesame seeds on top.Bake for about 20 minutes or until golden brown.
As soon as you take them out of the oven, brush with more milk.