Preheat the oven to 375°F (190°C). Coat the chicken pieces with 1 tablespoon olive oil and the fajita seasoning in a large bowl. Toss to make sure everything is coated evenly.

Heat 1 tablespoon olive oil in a large skillet over medium-high heat. Cook the seasoned chicken until browned and fully cooked, about 5-7 minutes. Remove the chicken from the pan and set it aside.

Add the remaining 1 tablespoon olive oil to the skillet and toss in the diced bell peppers and onion. Sauté for 5-6 minutes, or until the vegetables are slightly tender. Remove from heat.

Mix the softened cream cheese and sour cream in a large bowl until smooth. Stir in the chicken stock, instant rice, 1 cup of shredded Colby Jack cheese, cooked chicken, sautéed vegetables, salt, and pepper. Mix until everything is well combined. (The mixture will be liquidy at this point, but the rice will absorb the liquid as it bakes)

Lightly grease a 9x13-inch baking dish. Pour the mixture into the dish and spread it out evenly.

Top with the remaining 1 cup of shredded Colby Jack cheese. Cover the dish tightly with aluminum foil.

Bake for 20 minutes, then remove the foil and bake for another 10-15 minutes, or until the cheese is fully melted and bubbly.

Let the casserole sit for 5 minutes before serving to allow everything to set. Enjoy!