Cha gio is minced pork, herbs, and spices rolled up in rice paper then deep fried. Recently, cooks have been trading in their rice paper for a wheat based wrapper similar to egg rolls. They are easier to fry and stay crispy longer. The traditional Vietnamese way uses rice paper, which gets soggy after a while, but has a consistency that is much different than the egg roll type wrappers. I prefer the rice paper, but only when it's freshly fried.
In this dish, the chả giò is cut up and placed over vermicelli rice noodles, herbs, pickled daikon and carrot, and some greens. It's similar to bun thit nuong. They both come with nuoc cham, a sweetened fish sauce that can be used as a dip or spooned into the bowl. This sauce shouldn't be forgotten. Its sweet and sourness balances out the flavours. Sometimes the bowl will also have a variety of cha in it. If so, count yourself lucky and dig in.