Boil and mash the sweet potatoes.
Dissolve yeast and sugar in warm milk.
Mix flour, salt, mashed sweet potatoes, and the yeast mixture to make dough.
Let the dough rise for 30 minutes.
Divide the dough into small pieces and flatten them.
Add the filling (mashed sweet potatoes, nuts, brown sugar, etc.) on top and cover with dough.
Add oil to a pan and cook both sides over low heat until golden brown.