Set your Instant Pot to sauté. Add the butter and onion. Sauté for 2-3 minutes, until softened. Add in the garlic, carrots, celery, salt, basil, parsley and oregano and stir well. Continue cooking for 3-5 minutes.
Add in chicken breasts, rice and broth. Stir well.
Close the lid and set the vent to sealing. Pressure cook on high for 10 minutes.
At the end of cooking time, allow for 5-8 minutes of natural pressure release, then manually release the remaining pressure.
Remove the chicken breasts and shred. For easy shredding, transfer the chicken to a stand mixer and use the paddle attachment. Mix for 5-10 seconds for perfectly shredded chicken!
Add the chicken back into the soup along with the lemon juice and parsley. Serve hot.