Pork shanks are ideal for this recipe, but if you can't find pork shanks, pork should work work as well. Just make sure the pieces you choose have plenty of fat on them to keep the meat from drying out.
This recipe can also be used for lamb or veal shanks.
Always keep the pot covered while cooking in the oven to allow the steam to continue to braise the shanks.
If you can't find red miso, you can also substitute white or brown.