Start by making the pickled red onions. Add the sliced red onion to a bowl with apple cider vinegar, honey, salt, and pepper. Toss and set aside to pickle while you prepare everything else.
Preheat your oven to 400°F.
Add the sourdough cubes to a sheet pan, drizzle with olive oil, season with salt and pepper, and toss. Bake until golden and crispy, then set aside.
In a bowl or blender, make the Caesar dressing by combining mayonnaise, lemon juice, olive oil, garlic, Parmesan, Worcestershire sauce, Dijon mustard, and red wine vinegar. Blend or whisk until smooth and creamy.
In a separate bowl, toss the chopped romaine with lemon juice, Parmesan, and a few spoonfuls of the dressing. Mix until well coated and set aside.
In another bowl, combine the ground chicken with salt, pepper, oregano, dried basil, dried parsley, garlic powder, and onion powder. Mix until evenly seasoned.
Lay the tortillas flat on a parchment-lined baking sheet. Press a thin, even layer of the seasoned chicken directly onto each tortilla, spreading it edge to edge.
Bake for 25–30 minutes, or until the chicken is fully cooked and lightly golden. For extra crispiness, switch the oven to broil for 1–2 minutes at the end, keeping a close eye so they don’t burn.
Remove from the oven and top each taco with Caesar salad, croutons, and pickled red onions. Finish with extra Parmesan and dressing if desired.