In a small bowl, add warm milk, sugar, salt and yeast and stir until the sugar and yeast dissolves and rest for 10 minutes.
Sieve the flour in a large mixing bowl.
Then add dry milk, oil, melted butter and egg in it.
Add the yeast mixture in the flour and knead for few minutes.
Start kneading together and gradually add the water a little at a time.
You may not need to use all the water, so add it sparingly until your dough comes together and is nice and soft.
Knead for a good 8-10 minutes. The more you knead the dough, the softer the buns will be.
Touch a bit of oil with your fingertips and apply all over the ball of dough and trasnfer into a bowl.
Cover the dough with wet cloth and set aside for 1 hour for it to double in size.
Meanwhile, prepare your buns stuffing.
Peel potatoes and mash them roughly.
Melt 1 teaspoon butter in a frying pan over medium heat.
Add green peas, carrots and sweet corns. Cook and stir for few minutes until crispy-tender.
Now add green pepper, cabbage and green onions, cook for 2-3 minutes.
Add potatoes and a splash of soy sauce and hot sauce.
Season with salt and pepper.
Cook and stir for 2 more minutes or until all done.
Sprinkle the herb seasoning over it and turn the heat off and let it cool down completely.
Once dough risen, Punch it down and divide it into 18 small balls ( depending on the size of buns your would like).
Line the baking tray with baking sheets.
Roll out each ball into a circle.
Place vegetable stufing in the center, then ball it up and seal the edges.
Place it on the prepared baking tray and repeat it with remaining dough.
Cover the tray with a light cloth and let them rose for 30 minutes.
Now brush each buns with beaten egg.
Then sprinkle some sesame seeds all over.
Bake in the pre-heated (180 degree C) oven for 18-20 minutes or until buns turn golden brown.
Remove from the oven.
Brush butter on top of the buns and cover them with a cloth so they get really soft.
Serve warm and enjoy.