In a small bowl add 1½ teaspoons chili powder, 1 teaspoon paprika, ½ teaspoon sugar, ½ teaspoon cumin, ½ teaspoon onion powder, ¼ teaspoon salt, ½ teaspoon garlic powder and a pinch of cayenne pepper.
On a cutting board place the chicken breasts and if they are large, slice and then using wax paper, flatten the breasts into cutlets, roughly 5 ounces each. Sprinkle half the seasoning mixture on one side, turn over and sprinkle the remaining seasoning all over the chicken. Rub it in a bit.
In a large saute' pan add 2 teaspoons of the oil over medium-high heat. In a single layer add the chicken breast, in batches if need be. Cook for 4 minutes until golden brown, turning once and cooking on the other side for 3-5 minutes until cooked through. Remove to a plate and cover lightly to keep warm.
In the same pan add the other teaspoon of oil, if needed. and add the corn and cook, allowing it to get slightly browned, stirring occasionally for 4-5 minutes. Add the remaining ½ teaspoon of chili powder and stir till combined. Cook for another minute or two and then transfer to a medium sized bowl. Add the mayo and sour cream, the remaining salt and lime juice. Stir till combined. Add most of the Feta and most of the chopped cilantro. Save a little to sprinkle on top when serving.
place a piece of chicken and cover with a ¼ cup of corn mixture.