Cook the rice according to package instructions.
Grill the chicken breast until fully cooked.
Let the chicken rest for 5 minutes before slicing.
Grill the corn on the cob for about 10 minutes, rotating occasionally.
Cut the corn kernels off the cob after grilling.
In a large bowl, combine the cooked rice, sliced chicken, and corn kernels.
Add diced tomatoes, red onions, and cheese if desired.
Drizzle lime juice over the mixture and sprinkle with chili powder.
Toss gently to combine and season with salt and pepper.
Garnish with chopped cilantro before serving.