There has been a lot of confusion recently about what dishes at P.F. Chang's are truly vegan, not just vegetarian. Turns out the only two confirmed vegan dishes offered on the menu are the Garlic Snap Peas and the Buddha's Feast.
So what keeps the vegetarian dishes from being vegan? Egg and chicken stock unfortunately. The marinades and sauces used in the kitchen heavily depend on both.
The good news is both dishes are gluten free (and delicious) so at least you don't have to waste time pouring over the menu, deciding what to order.