Set the Instant Pot to Sauté. Add olive oil.
Sear chicken thighs for 3–4 minutes per side until lightly browned. Remove and set aside.
Press Cancel to turn off Sauté mode. Add rinsed rice, broth, salt, pepper, garlic powder, onion powder, and thyme (if using). Stir gently to combine.
Sprinkle the frozen vegetables evenly on top of the rice — do not stir.
Place the browned chicken thighs on top (bone side down). Do not press down or mix in.
Secure the lid and set the valve to Sealing. Cook on High Pressure for 12 minutes
Let the pressure release naturally for 10 minutes, then quick release any remaining pressure.
Carefully remove the chicken. Fluff the rice with a fork and serve warm.