BBQ Chicken Salad

Flatten the Chicken - Place one of the chicken pieces between two plastic sheets or in a large plastic bag. Use a meat tenderizer to flatten to an even thickness, about ½-inch thick. Repeat with the remaining piece.
Season the Surface - In a small bowl, combine ¾ teaspoon salt and ½ teaspoon black pepper. Evenly season both sides of the chicken with the mixture.
Cook the Chicken - Heat a large skillet or grill pan over medium heat. Add olive oil, and heat until hot and shimmering but not smoking. Add the chicken and press down for maximum contact. Cook until golden brown, about 5 to 8 minutes. Flip and cook until the internal temperature reaches 160 to 165ºF (71 to 74ºC) on a meat thermometer, about 5 to 8 minutes. Transfer to a clean plate to rest for 5 minutes.
Rest and Slice - Rest the chicken for 10 minutes. Once cool enough to handle, slice against the grain. If desired, chop into cubes. Set aside or refrigerate until ready to serve.
Make the Dressing - In a medium bowl, combine the ranch dressing and barbecue sauce. Set aside or cover and refrigerate until ready to serve.
Dress the Salad - Add romaine lettuce to a large bowl and ¼ cup of dressing, gently toss to combine.
Add the Toppings - Top the salad with tomatoes, corn, black beans, cheddar cheese, tortilla chips, red onion, and sliced chicken. Serve with remaining dressing on the side. If desired, drizzle extra barbecue sauce and ranch on top.