This is my favourite Chinese Dim-Sum. It is a steamed cake of rice flour and grated Chinese radish (lo-bak), which is then cut into slices and pan fried. Not unlike scrapple, in some ways, although less meaty. It's delicious with lots of hot sauce. Lo-bak looks very similar to daikon; it is just a little bit milder in flavour. I suspect daikon would work okay if need be. You don't have to use both the shrimp and the shiitake; one or the other would be alright.