Place all of the stock ingredients in your slow cooker and set to low. Placing all the spices and the cilantro roots in a cheesecloth pouch makes it easy to pull them out later.
After about 8 hours, remove all of the solids from the stock and add the bok choy.
Cool the chicken slightly until you can pull the meat off, shred and return to the stock.
Meanwhile, cook udon noodles as directed on package, drain and add to slow cooker.
Spoon into bowls and top with fresh red chili and fresh cilantro.