Roasting a chicken rather than just getting frozen shredded chicken is an A+ move. Also, after going over it with my girlfriend I misspoke in my last comment. The order should be thicken and then season. I just do the whole process on auto pilot at this point and I'm not used to typing it out. I'll have to seek out that spice blend. I always like testing out new stuff like that. I highly suggest trying to find some filé powder (also called filé gumbo). It's a very subtle flavor that you have to use a lot of for it to make a difference but it really takes it to another level.