Make the dressing. In a small blender or food processor, blend the mayonnaise, parmesan, garlic, capers, mustard, lemon zest, lemon juice and black pepper.
Cook the pasta. Bring a large pot of heavily salted water to a boil. Cook pasta according to package directions and drain.
Make the croutons. Preheat oven to 400°F. On a baking sheet, toss cut sourdough bread with oil and kosher salt. Bake until golden brown, 15 minutes.
Assemble salad. In a large bowl, mix pasta, croutons, romaine lettuce, chicken, and dressing. Season to taste and serve immediately.
Video
Notes
Make ahead: You can cook the chicken ad croutons and make the dressing ahead of time.Storage: Undressed, the salad will keep well covered in the fridge for around 3 days. Don't dress the salad until you are ready to serve it.