To a small bowl, add chili powder, cumin, salt, and garlic powder. Stir to combine. Divide in half and set aside.
To a medium bowl, add chicken and half of the seasoning mixture. Stir to combine.
To a large 13-inch skillet, add olive oil and butter. Once the butter has melted, add chicken to the pan in an even layer to ensure even cooking. You may have to cook in batches. Cook 8-10 minutes, flipping halfway through, or until all sides are golden brown and the chicken is cooked through to an internal temperature of 165°F. Remove to a plate and tent to keep warm. Set aside.
Add the onion and peppers. Cook, stirring occasionally until softened (about 3-4 minutes).
Add the garlic and cook for 1 more minute.
Stir in the uncooked rice and the remaining seasoning mixture.
Pour in the chicken broth and bring the mixture to a boil. Once boiling, reduce the heat to low, cover, and simmer for 15-20 minutes, or until the rice is tender and the liquid has been absorbed.
Add the salsa, corn, black beans, heavy cream, and cooked chicken to the skillet. Stir to combine well and continue cooking, uncovered, until everything has warmed through.
Garnish with cilantro. Serve warm.