In a medium saucepan, combine the rinsed quinoa and water. Bring to a boil over medium-high heat.
Once boiling, reduce heat to low, cover, and simmer for 15 minutes or until the quinoa is tender and water is absorbed.
Remove from heat and let quinoa sit covered for 5 minutes, then fluff with a fork.
While quinoa cooks, prepare the chicken. In a small bowl, mix chili powder, ground cumin, smoked paprika, garlic powder, onion powder, salt, and black pepper.
Rub the spice mixture evenly over both sides of the chicken breasts.
Heat olive oil in a large skillet over medium-high heat.
Add the chicken breasts and cook for 6-7 minutes per side, or until the internal temperature reaches 165°F (75°C) and the chicken is cooked through.
Remove chicken from skillet and let rest for 5 minutes, then slice into strips.
In a medium bowl, combine black beans, corn, cherry tomatoes, red onion, cilantro, and lime juice. Stir gently to combine.
To assemble the bowls, divide the cooked quinoa evenly among four bowls.
Top each bowl with sliced chicken, black bean and corn salsa mixture, sliced avocado, and shredded cheddar cheese.
Add a dollop of sour cream if desired.
Serve immediately and enjoy your Mexican Chicken Quinoa Bowl.