Sauté Chicken and Aromatics: Set the Instant Pot to "Sauté" mode. Add olive oil and heat. Add chicken and sauté until lightly browned on all sides. Remove chicken from the pot and set aside. Add chopped onion to the pot and sauté until softened, about 3-5 minutes. Add minced garlic and cook for another minute until fragrant.
Combine Ingredients: Add the rice, chicken broth, Italian herbs, salt, and pepper to the Instant Pot. Stir well to combine. Return the browned chicken to the pot, nestling it down into the rice mixture. If using frozen peas or vegetables, add them now.
Pressure Cook: Close the Instant Pot lid and set the valve to "Sealing." Cook on high pressure for 10 minutes for white rice (or see notes for brown rice).
Natural Pressure Release: Allow the Instant Pot to naturally release pressure for 10 minutes, then carefully quick release any remaining pressure.
Fluff and Serve: Open the lid and fluff the rice with a fork. Check the chicken to make sure it is cooked through (internal temperature of 165°F). If desired, stir in additional frozen vegetables at this point. Serve hot.