In a medium bowl, combine shredded cooked chicken breast with Caesar dressing, mixing until each piece is well coated. Set aside to allow flavors to meld while preparing other components.

Heat a skillet over medium heat and add olive oil. Once the oil shimmers, add the chicken mixture to the skillet. Stir occasionally and cook for 3-5 minutes until warmed through.

Slice the croissants in half horizontally. Spread unsalted butter evenly on the inner sides. In the same skillet, toast the croissants, buttery side down, for about 2 minutes.

Layer the bottom halves of the toasted croissants with chopped Romaine lettuce.

Distribute the warm chicken mixture evenly over the Romaine lettuce in each croissant.

Sprinkle freshly grated Parmesan cheese generously over the chicken layer, then add halved cherry tomatoes.

Season with a pinch of salt and pepper. Place the top half of the toasted croissant onto each sandwich and serve immediately.