Place chicken into Instant Pot. Add in the kosher salt, pepper, dill, garlic powder. Toss the chicken to coat in the seasonings. 

Add in egg noodles on top of chicken in an even layer. Then pour the broth over the top. Add mushrooms on top of the noodles in an even layer. 

Secure the lid and make sure valve is set to seal. Set the manual/pressure cook button to 2 minutes. Allow a natural pressure release for 10 minutes then move the valve to vent to releave any excess pressure. Remove the lid.

Stir the contents of the pot. In a bowl, add ¼ cup of liquid from pot to the sour cream and stir to temper it. Then add the sour cream into the pot. If needed, in a small bowl, combine the cornstarch and water together until smooth. (Mine was thick enough so I didn't need the slurry). Turn Instant Pot to saute and add in the cornstarch slurry. Contents of pot will thicken quickly. Turn off Instant Pot.

Add in the Worcestershire sauce. Scoop onto plates and serve.  Serves 4-6.