Cook the Rice: In a large pot or deep skillet, heat 2 tablespoons of oil over medium heat. Add the diced onion and cook for 2 to 3 minutes until softened. Stir in the rice and toast for 5 to 6 minutes, stirring often, until lightly golden. Add tomato sauce, water, and bouillon powder. Bring to a simmer, then reduce heat, cover, and cook according to rice package instructions until the rice is fluffy and the liquid is absorbed.

Cook the Chicken: While the rice cooks, heat 1 tablespoon of oil in a separate skillet over medium-high heat. Add the diced chicken and sprinkle evenly with the fajita seasoning. Cook for 7 to 8 minutes, stirring occasionally, until the chicken is fully cooked and reaches an internal temperature of 165 degrees Fahrenheit.

Heat the Queso: In a small saucepan or in the microwave, warm the cheese dip according to package instructions until it is hot and pourable.

Assemble and Serve: Spoon a generous portion of the cooked rice onto plates or into bowls. Top with the fajita-seasoned chicken, then drizzle generously with the warm queso. Serve immediately.