Warm avocado oil in a medium nonstick skillet over medium heat. When oil is hot, add chili powder, ground cumin, garlic powder, salt, and cayenne pepper. Stir spices in heated oil until fragrant, 2 to 3 minutes.
Add chicken and toss gently to coat in oil and spice mix. Cook, stirring, until chicken is warmed through, about 4 minutes. Sprinkle lime juice over chicken, remove to a plate, and keep warm.
For street corn, add corn kernels to the same skillet, and increase heat to medium-high. Cook until corn starts to pop and picks up a little color, 3 to 5 minutes.
Place skillet-roasted corn in a bowl, and add red onion, 1/2 cup sour cream, mayonnaise, cotija cheese, chili powder, salt, pepper, and cayenne pepper, to taste.
To assemble the bowls, spread each bowl with a bed of shredded lettuce. Add seasoned chicken, a serving of Mexican rice, and a serving of the street corn.
Garnish with lime wedges, fresh cilantro, and pico de gallo.
Place a dollop of sour cream in the center of each bowl, sprinkle with some additional cotija cheese, and serve.
