Turn the Instant Pot on the saute setting and melt the butter. Add the sliced celery, diced onion, and sliced carrots to the Instant Pot. Saute for about 5 minutes or until the onion is starting to get translucent.
Add the salt, ground pepper, and ground thyme and mix.
Add the boneless chicken breasts, bay leaves and rosemary sprig to the Instant Pot. Pour the chicken broth in and mix to combine.
Place the lid on the Instant Pot and make sure it is engaged properly. Set the valve to the sealing position.
Press the manual button and set the pressure cooking time to 8 minutes.
Once the Instant Pot has finished pressure cooking allow the pressure cooker to naturally release the steam for 8 minutes.
Use the handle of a wooden spoon to push the valve to the venting position and allow the remaining steam to release. Carefully open the lid of the Instant Pot and lift it so the steam escapes away from your face to prevent a burn.
Remove the pressure cooked chicken pieces from the Instant Pot and place them in a bowl.
Use two forks to shred the pressure cooked chicken meat. Return the cooked chicken to the Instant Pot.
Add 1 ½ cups of extra wide egg noodles to the Instant Pot and mix to combine.
Place the lid back on the Instant Pot and push the vent to the sealing position. Allow the Instant Pot to sit undisturbed for 12 minutes to cook the wide egg noodles.
After 12 minutes open the Instant Pot and check the noodles to see if they are done enough for your tastes. If the noodles need to cook a bit more replace the Instant Pot lid and wait another minute or two. (See Notes on Noodles)
Makes 6 servings.