In a medium bowl, whisk together 1 tablespoon lime juice, 1 tablespoon avocado oil, 1 teaspoon chili powder, 1 teaspoon ground cumin, 1/2 teaspoon garlic powder, 1/2 teaspoon salt, and 1/4 teaspoon black pepper. Add the 4 chicken thighs and massage the marinade into the meat. Cover and refrigerate for 15 to 30 minutes.

While the chicken marinates, heat a dry skillet over medium-high heat. Add the frozen corn kernels and cook for 4 to 5 minutes, stirring occasionally, until some kernels develop golden-brown charred spots. Transfer to a bowl and set aside.

In the same skillet over medium-high heat, place the marinated chicken thighs without crowding. Sear undisturbed for 8 to 10 minutes until golden-brown on the bottom. Flip and cook for another 8 to 10 minutes until internal temperature reaches 165°F. Transfer to a cutting board and let rest for 5 minutes before slicing into thin strips.

While chicken cooks, make the street corn mixture. In a bowl, combine charred corn, 1/4 cup red onion, 1/2 cup sour cream (minus 2 tablespoons for garnish), 2 tablespoons mayonnaise, 1/2 cup cotija cheese, and 1 teaspoon chili powder. Season with salt and pepper, add 1 tablespoon lime juice, and stir until creamy. Taste and adjust seasoning.

If rice is cold, warm it in a microwave-safe bowl with 2 tablespoons water, covered with a damp paper towel, for 2 to 3 minutes. Or reheat in a saucepan with a splash of water over medium heat. Fluff with a fork.

To assemble, divide warm rice among four bowls. Top each with sliced chicken and a scoop of street corn mixture. Sprinkle extra cotija cheese and cilantro over top. Place lime wedges on the side. Drizzle reserved sour cream and add Tajín or chili powder if desired. Serve immediately.