Preheat a grill to medium-high (about 450 degrees) Coat a cold cooking grate with cooking spray, and place on the grill. Place the corn on the cooking grate, and grill covered, 12 minutes, turning every 2 to 3 minutes until done. Let stand 5 minutes.
Season the chicken with the salt and pepper (I used fajita seasoning). Grill the chicken, covered, 5 minutes on each side or until done.,
Cut the kernels from the cobs. Discard the cobs. Chop the chicken into 1-inch cubes.
Combine the lettuce, tomatoes, avocado, red onion, and black beans on a large serving platter. Top with the grilled corn and chicken. drizzle with the desired amount of Chipotle Dressing.