Pour boiling water over mushrooms and let sit for 20 minutes, until mushrooms have reconstituted.
Heat oil. Saute ginger and shallots a few minutes, until softened. Add mushrooms and saute for another 2 minutes. Add bok choy, soy sauce, vinegar and sugar.
Cook until bok choy leaves have wilted.
Add salt, to taste. Cool.
In a small bowl, dissolve tapioca into water until you have a slurry. (egg can also be used)
Heat oil for deep frying.
On a flat surface, lay down a wonton skin. Place a spoonful of filling on the skin. Fold over into a triangle, making sure the filling is tight. Brush the ends with the tapioca slurry. Fold in the sides. Roll.
Place in hot oil and fry until golden brown.
Serve with your favorite dumpling sauce.