Roll out the dough using a pasta roller, starting at setting 0 and working up to setting 3. Then roll it out further using a rolling pin until very thin.
Using a circular cutter, cut out dough circles. Add filling to the centre of each circle.
Shape each one into a boat-shaped mantu. Before folding, lightly spritz the edges with water to help seal the mantu and make the process easier.
Set the finished mantu aside on a plate and cover them to prevent drying out.