Grill or cook the chicken breasts, season with salt, pepper, and chili powder, then dice into bite-sized pieces.
In a bowl, combine corn kernels, mayonnaise, sour cream, lime juice, chili powder, and cilantro. Stir well and season with salt and pepper.
Divide cooked rice into serving bowls. Add chicken and the prepared street corn mixture on top.
Sprinkle with crumbled cotija cheese, additional cilantro, and optional toppings like diced avocado or jalapeños.
Serve warm and enjoy!
