Preheat oven to 350.
Pound chicken breasts to an even thickness; do not pound thin.
In a large ziploc bag, combine chipotle powder, cumin, salt and chicken; close bag and using your hands, massage the seasonings around the chicken pieces. Let stand 5 minutes.
Grease a grill pan with cooking spray and set it over medium-high heat.
Add chicken pieces and cook for 4 minutes; flip, and continue to cook for 2 more minutes, or until lightly browned.
Place grill pan in the oven and cook for 18 to 20 minutes, or until chicken is cooked through.
Remove from oven and let stand 5 minutes.
In the meantime, prepare the salad.
In a large salad bowl, toss together salad greens, corn kernels, diced avocados and chopped tomatoes.
Cut up the chicken and layer it on top of salad.
Sprinkle with cheese.
Toss with your favorite b][salad dressing