Turn the Instant Pot to the 'Saute' setting and add the oil and butter. Stir until butter has melted. Add the onion, carrots, and celery and saute for about 3 minutes, or until the onions soften. Add the garlic and saute for about 30 seconds.
Season with salt and pepper, and add thyme. Season the chicken thighs with salt and pepper on both sides and add them to the pot. Pour carefully the chicken broth and water.
Close the lid and set the Instant Pot to the 'Soup' setting and set the timer to 10 minutes.
Once the Soup cycle is complete do a Quick Release. Carefully unlock and remove the lid. Remove the chicken thighs from the soup and place on a cutting board.
Add the egg noodles to the soup and press the 'Saute' setting. Cook the noodles uncovered for about 6-7 minutes.
While the noodles are cooking, shred the chicken. Once noodles are done, stir in lemon juice, shredded chicken and parsley. Serve warm.