Purple Sweet Potato Buns

Recipe

Ingredients
150g     bread flour
1/2tsp   instant yeast
20g       sugar
65-70g  milk (warm)
28g       egg
1/2tsp   salt
50g       cooked purple sweet potato (mashed)
8g         butter

Steps:
1. Dissolve yeast in warm milk and set aside.
2. In a big mixing bowl mix flour, sugar, mashed purple sweet potato and salt together.
3. Make a well in middle of flour mixture, pour in milk and egg.
4. With a spatula, mix ingredients together till it form a dough. 
5. Lastly, add in butter and knead into dough.
6. Place dough on table top and hand knead till it achieve a smooth and elastic dough. (dough will be sticky)
7. Put dough in a bowl, cover and let it proof for an hour.
8. Knock down proof dough, hand knead on a lightly floured surface for a while.
9. Divide dough into 6 portions about 52g each, cover and rest for another 20mins.
10.Shape each dough into round ball and arrange them in a greased pan 21cm x 16cm.
11.Cover and leave it to proof for an hour until it doubled in size.
12.Preheat oven to 170C.
13.Brush surface with milk and bake in a preheated oven for 14mins until buns surface is browned.

14.Remove buns from pan and cool it on wire rack.