In a medium bowl, add 1 ½ cups cooked rice and stir in 1 tablespoon lime juice (reserve the rest of the lime juice for later), ½ teaspoon salt, and chopped cilantro. Set aside.
Heat 1 tablespoon olive oil in a large skillet over medium-high heat. Add the chicken pieces and season with chili powder, cumin, paprika, garlic powder, salt, and pepper. Stir well to coat the chicken with the spices. Cook the chicken for about 7-8 minutes or until browned and fully cooked through, stirring occasionally. Once the chicken is cooked, squeeze the remaining 2 tablespoons lime juice over the chicken and toss to combine. Remove from heat.
While the chicken is cooking, preparethe toppings: Dice the tomato and chop the onion, drain and rinse the black beans, heat the corn in the microwave or a small pan until warmed through.
To serve, divide the rice evenly between 4 bowls. Top each bowl with an even portion of the seasoned chicken. Add the corn, black beans, tomato, and red onion on top of the chicken and rice. Sprinkle with shredded cheddar cheese and sour cream or whatever other toppings you prefer. Garnish with fresh cilantro leaves and lime wedges if desired.