Prepare the Chicken - Place one of the chicken pieces between two plastic sheets or in a large plastic bag. Flatten to an even thickness with a meat tenderizer, about ½-inch thick. Repeat with the remaining piece.
Mix the Seasonings - In a small bowl, combine salt, black pepper, garlic powder, and onion powder. 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. Cook until golden brown, about 5 to 7 minutes. Flip and cook until the internal temperature reaches 160 to 165ºF (71 to 74ºC) on a meat thermometer, about 5 to 7 minutes.
Rest then Slice - Rest the chicken for 10 minutes. Slice the meat against the grain, then cut it into cubes. Refrigerate until ready to use.
Dress the Lettuce - Add romaine lettuce to a medium bowl and drizzle with ¼ cup of dressing. Gently toss to combine.
Warm the Tortillas - In a large non-stick pan, warm the tortillas over medium heat until pliable, about 15 to 30 seconds per side. Cover with a kitchen towel to keep them soft and flexible.
Assemble the Wrap - Evenly divide the dressed lettuce in the tortillas. Top with the diced chicken, tomatoes, and parmesan cheese. Drizzle some of the remaining dressing on top or serve on the side. Add the croutons. Fold in the sides and tightly wrap into a cigar shape. Slice and secure with toothpicks if needed.
Notes
Storing: Undressed wraps can be tightly covered and stored in the refrigerator for up to 3 days. The dressing can be made 3 days in advance.