I have been meaning to make a proper Chashu for a long time. Until now I have just used pork tenderloin, chicken, beef steak or ground pork thrown into the sous-vide with some garlic, ginger, honey and soy sauce. This was mainly due to my laziness, as there is only 1 proper butcher near where I live and the super markets rarely have pork belly in stock. Recently one of my local supermarkets has started stocking all sorts of cuts of meat, stock bones, pork fat, all the good stuff you need to make a proper bowl of ramen.
Anyway, I'm going to keep this short and sweet. This is basically a mix of two recipes, the first, I used the ingredients common to nearly every Chashu recipe that you will find online. The second I used the technique of a 36hr sous-vide and deep fry from a recipe on Serious Eats.
You are going to need some cotton twine to tie the pork into a roll.