Season chicken thighs on both sides with salt and pepper.

Select 'Saute' on the Instant Pot. Allow it to heat. The display will indicate 'Hot' when ready.

Add olive oil to the pot. Once hot, add the chicken meat-side down. Do not move. Cook until the surface lightly browns, about 3 minutes. Use a spatula to release any meat sticking to the pan. Flip and cook for 2 minutes. Transfer to a clean plate.

Add onions and saute until tender, 1 minute. Add celery and carrots, saute for 1 minute. Add garlic, thyme, rosemary, salt, pepper, and saute for 30 seconds.

Add 1 cup of chicken stock to the pot, use a spoon to scrape away any browned bits on the bottom. Press 'cancel' on the Instant Pot.

Add reserved chicken, bay leaves, and the rest of the chicken stock to the pot. Make sure that the release valve is in the 'Sealing' position. Place the lid on the Instant Pot, turn and lock. Press the 'Manual' button on the Instant Pot on high pressure, and then set the timer to 7 minutes using the '+' or '-' buttons.

It will take about 15 to 20 minutes for the pot to heat up and build up pressure. You will see steam release from the lid, and then the time will start on the display.

Once cooking time is complete, naturally release for 10 minutes. Cover the valve with a kitchen towel. Use an oven mitt or towel to gently twist the steam release handle on the lid to the 'Venting' position. The initial release will spray moisture around. Carefully remove the cover, opening the top away from you as steam does release.

Remove the chicken from the pot and transfer it to a cutting board. Once cool enough to handle, discard the bones and shred them into smaller pieces with a fork.

Remove the bay leaves from the pot and discard them. Select 'Saute' on the Instant Pot. Once the stock starts to boil, add noodles, stir and cook until tender, about 7 to 8 minutes.

Add the shredded chicken to the pot. Season with salt and pepper to taste. Garnish soup with chopped parsley.