How to Make It
Preheat oven to 425°F. Place a lightly greased wire rack in an aluminum foil-lined rimmed baking sheet. Stir together panko, pecans, paprika, 1 teaspoon of the salt, and 1⁄2 teaspoon of the pepper in a bowl. In a separate bowl, whisk egg whites just until foamy. Place flour in another bowl.
Sprinkle chicken with 1⁄2 teaspoon of the salt. Dredge chicken in flour; dip in egg whites, and dredge in panko mixture, pressing to adhere. Coat chicken on each side with cooking spray; place on rack. Bake in preheated oven until done, 20 minutes, turning after 12 minutes. Slice chicken.
Meanwhile, heat a grill pan over medium-high. Coat cut sides of lettuce with cooking spray. Place lettuce, cut side down, on pan. Grill until marks appear, 3 minutes. Chop lettuce; place in a large bowl. Coat onion slices and corn with cooking spray. Grill onion until marks appear, 3 minutes per side. Grill corn, turning, until charred, 5 minutes. Cut kernels from cob; discard cob.
Whisk together buttermilk, next 4 ingredients, and remaining 3⁄4 teaspoon salt and 1⁄2 teaspoon pepper.
Toss together lettuce, tomatoes, and 1⁄4 cup dressing; arrange on a large platter. Top with onion, corn, chicken, bacon, croutons, and avocados. Serve remaining dressing on the side.