01 - Combine olive oil, chili powder, smoked paprika, cumin, garlic powder, salt, pepper, and lime juice in a bowl. Add chicken and toss to coat thoroughly. Let marinate for at least 15 minutes, up to 2 hours for enhanced flavor penetration.
02 - Rinse rice under cold water until water runs clear. Bring water to a boil in a saucepan, add rice and salt. Cover tightly, reduce heat to low, and simmer for 15 minutes until tender and liquid is absorbed. Fluff with a fork before serving.
03 - Heat a grill pan or skillet over medium-high heat. Cook marinated chicken for 5–6 minutes per side until internal temperature reaches 165°F. Remove from heat and let rest for 5 minutes to allow juices to redistribute, then slice against the grain.
04 - Melt butter in a skillet over medium-high heat. Add corn kernels and cook for 4–5 minutes until slightly charred. Remove from heat and immediately stir in mayonnaise, sour cream, cotija cheese, minced garlic, chili powder, lime juice, salt, and pepper until well combined.
05 - Divide cooked rice evenly among 4 serving bowls. Arrange sliced chicken, street corn mixture, diced avocado, cherry tomatoes, and fresh cilantro on top. Garnish with additional cotija cheese if desired and serve with lime wedges for squeezing.