seitan pork belly

I'm on a mission to veganize Chinese pork belly. They're already doing this in China. I can make pretty good seitan and I think the slow cooker seitan tied in a cloth cooking method would be good for the "meat" part but what about the fat part? From the picture in the blog, it looks like maybe some rice flour/fat mixture was used. I tried once by making a super soft layer of seitan around the "meat" layer by adding more oatmeal and more water. It was okay but not great. There was not enough delineation of texture. Perhaps a layer of frozen tofu mixed with a binder might be good.