In a skillet pan over medium heat, heat oil. Add cooked and shredded chicken, cumin, chili powder, garlic powder, salt, and pepper. Stir and cook until completely heated through and all the chicken is coated in seasonings. Remove from heat, cover with aluminum foil to keep warm, and set aside while you prepare the corn.
In another skillet (or you can use the same skillet you heated the chicken in), heat oil over medium heat.
Add frozen corn and let cook until corn starts to char, stirring occasionally (it took about 7-8 minutes before my corn was lightly charred).
While the corn is cooking, mix together mayonnaise, cheese, lime juice, jalapeno, cilantro, red onion, garlic, chili powder, salt, and pepper in a large bowl. When corn is done, gently fold it in with other ingredients.
Lay tortilla out on a plate. Top with 1/2 cup chicken, some Mexican street corn, sliced avocados, cotija cheese, and fresh cilantro.
Notes
You can also buy frozen street corn from Costco and use that in place of making it from scratch.If you are short on time, use a rotisserie chicken from the grocery store.