Textured Vegetable Protein or Textured Soy Protein
I find it in the section of some grocery stores where they have the healthy foods or the flours and baking section sometimes...It's usually mixed in with the "rye, barley and whole grain type flours and baking stuff...It is labeled "TVP", if they have it. Ask your store...sometimes they will order it.
It's just as easy to get an order in online and it's not expensive at all...