Step 1: Heat 2 tablespoons of olive oil in a large skillet or Dutch oven over medium heat. Add the diced chicken breasts and season generously with salt, pepper, garlic powder, and onion powder. Sauté for 5-7 minutes, stirring occasionally, until the chicken is golden brown and cooked through. Remove the chicken from the skillet and set aside.
Step 2: In the same skillet, add the 1 cup of long-grain white rice and dried thyme. Stir for about 1 minute to lightly toast the rice. Pour in the 2 cups of chicken broth, scraping up any browned bits from the bottom of the pan. Bring the mixture to a boil.
Step 3: Once boiling, reduce the heat to low, cover the skillet tightly, and let it simmer for about 15 minutes, or until the rice is tender and has absorbed most of the liquid. Avoid lifting the lid during this time to ensure even cooking.
Step 4: Once the rice is cooked, stir in the 1 cup of heavy cream (or half-and-half) and the 1 cup of frozen mixed vegetables. Return the cooked chicken to the skillet. Mix everything well and continue to cook for another 5 minutes, or until the vegetables are heated through and the sauce has thickened to a creamy consistency.
Step 5: Remove the skillet from the heat. Taste and adjust seasoning with additional salt and pepper if needed. Garnish with fresh chopped parsley, if desired, and serve immediately. Enjoy your perfectly creamy and satisfying meal!