Rinse the rice under cold water until the water runs clear, then drain. This helps keep the grains from becoming gummy.
Set the Instant Pot to the sauté function. Add olive oil, then sauté the onion until it’s translucent and fragrant, about 3–4 minutes. Stir in the garlic for a minute more.
Add the chicken pieces to the pot and cook until they’re lightly browned on the outside, about 5 minutes. They don’t need to be fully cooked through at this stage.
Stir in paprika, thyme, black pepper, and salt. Pour in the chicken broth and scrape up any flavorful browned bits from the bottom of the pot.
Add the rinsed rice to the pot and give it a gentle stir to distribute evenly. Layer the frozen vegetables on top; there’s no need to thaw them.
Close the lid and set the valve to sealing. Pressure cook on high for 6 minutes. When the timer goes off, let the pressure release naturally for 10 minutes, then do a quick release for any remaining pressure.
Open the lid and stir the mixture. If you’d like extra creaminess, fold in the cream cheese or sour cream while the pot is still warm. Add lemon juice to brighten the flavors, if using.
Taste and adjust seasoning with a pinch more salt or pepper as needed. Serve hot, with a light sprinkle of chopped parsley or chives if you have them.