Season turkey thighs on both sides with above seasonings and put into a slow cooker, along with the onion, water, Worcestershire and mushrooms. Cook on high for 1 hour, and then turn to low and cook for 4 hours.
After time is up, remove turkey thighs from the broth and let them cool in a bowl. When cool enough,
remove the meat from the bones and with two forks, shred the turkey meat, much like pulled pork. Set aside.
To the broth in the slow cooker, add the can of soup and sour cream, mixing very well. Make a slurry with the cornstarch (add a few drops of water and stir till smooth) and add it to the broth to thicken.
After sauce is thickened, add the turkey back to the pot and cover. Taste for seasoning and adjust. Cook an additional 20 min on low.
Meanwhile, cook the egg noodles according to the package directions and drain. Return them to the pot and add the butter to melt over the pasta.