In a large mixing bowl, toss the cubed chicken breast with olive oil, garlic powder, chili powder, smoked paprika, cumin, salt, and pepper until evenly coated.
Heat a large non-stick skillet or cast-iron pan over medium-high heat. Add the chicken in a single layer and sear for 4–5 minutes per side until golden brown and the internal temperature reaches 165°F (74°C). Remove chicken from the pan and set aside.
In the same skillet, add the corn kernels. Cook undisturbed for 2–3 minutes to achieve a slight char, then stir and cook for another 2 minutes. Remove from heat.
In a medium bowl, whisk together the Greek yogurt, lime juice, lime zest, and Tajín seasoning to create the dressing.
Fold the charred corn, diced jalapeño, chopped cilantro, and crumbled cotija cheese into the yogurt dressing until well combined.
Assemble the bowls by portioning 3/4 cup of cooked rice into four bowls. Top each with 1/4 of the cooked chicken and a generous scoop of the street corn mixture.
Garnish each bowl with fresh avocado cubes and an extra sprinkle of Tajín or cilantro before serving.