01 - Whisk together olive oil, chili powder, smoked paprika, cumin, garlic powder, salt, pepper, and lime juice in a bowl. Add chicken and coat thoroughly. Marinate for at least 15 minutes, up to 2 hours for enhanced flavor.
02 - Rinse rice under cold water until water runs clear. Bring water to boil in a saucepan, add rice and salt. Cover, reduce heat to low, and simmer for 15 minutes until rice is tender and liquid absorbed. Fluff with fork.
03 - Heat grill pan or skillet over medium-high. Cook chicken 5–6 minutes per side until internal temperature reaches 165°F. Let rest for 5 minutes before slicing against the grain.
04 - Melt butter in skillet over medium-high heat. Add corn and cook 4–5 minutes until lightly charred. Remove from heat. Stir in mayonnaise, sour cream, cotija, garlic, chili powder, lime juice, salt, and pepper until combined.
05 - Divide rice among 4 bowls. Arrange sliced chicken, street corn mixture, avocado, tomatoes, cilantro, and additional cotija on top. Serve with lime wedges for squeezing.