Firstly in a small saucepan, place the tangzhong ingredients and place the pan on medium heat until it forms a small dough (This will take about 1-2 minutes)
In a separate bowl add the yeast, sugar, warm milk in a small bowl and mix well and leave aside for 10 minutes until it is foamy
In a stand mixer with the dough attachment, place flour, salt, butter,sugar and egg, mix well
Once the yeast has froth, then add the yeast mixture and the tangzhong and knead well for 5 minutes ( if using hands, Add oil to the work surface and transfer the dough on to the surface and knead for about 10-15 minutes until smooth
Brush a bowl with oil and place the kneaded dough inside, cover with a cling wrap or damp cloth and let it rest and double in size in a warm area. ( Note: it may take longer than a usual dough as it is a very sticky and has a high moisture content. The resting time will depend on the humidity and temperature
Once doubled in size knock the air out by punching the dough and cut it into 6 equal pieces
Using your palm in a circular motion, make smooth balls by pressing it downwards and rotating it in one place
Place them on a tray leaving small gaps in between and cover with a damp cloth. Let it rise for the second time in a warm area until doubled in size ( you don't need to leave it for a long time, this will take half the amount of time it took for the first rise )
Preheat your oven to 190 Degrees (conventional)
Once the dough has risen egg wash ( whisk 1 egg with a splash of milk) and sprinkle sesame seeds on the top just before putting it in the oven
Bake for 13-15 minutes in the middle rack of the oven until the top has a beautiful golden brown colour
Once it comes out of the oven, brush melted butter on the top .Let it cool down