Season the boneless skinless chicken with salt and pepper, then sear in olive oil over medium-high heat for about 4-5 minutes on each side until golden brown and cooked through (internal temperature of 165°F). Set aside to rest.

In the same pan, melt a tablespoon of butter (if desired) and sauté the chopped onion until it becomes translucent, which should take about 2-3 minutes. Add minced garlic and optionally sliced mushrooms, cooking until fragrant.

Stir in the long-grain white rice and toast it in the pan for about 1-2 minutes, ensuring the grains are slightly coated with the flavors.

In a bowl, mix together the cream of chicken soup, sour cream, garlic powder, onion powder, dried thyme, paprika, and cayenne pepper until smooth and creamy.

Pour low-sodium chicken broth and heavy cream over the toasted rice in the pan. Stir everything together, then nestle the seared chicken back into the mixture. Bring to a gentle simmer.

Cover the pan and reduce the heat to low, simmering for about 20-25 minutes until the rice absorbs the liquid and turns fluffy.

After removing from heat, let rest uncovered for 5 minutes. Garnish with fresh chopped parsley for a vibrant touch just before serving.