In a shallow bowl or dish, combine the chicken breasts and Caesar salad dressing. Cover and marinate for at least 30 minutes.
Heat the olive oil in a large skillet over medium-high heat. Add the marinated chicken breasts and cook until golden brown, about 5 minutes per side.
To assemble the sandwiches: spread 1 tablespoon of Caesar salad dressing on each slice of bread. Layer each slice with lettuce, Parmesan cheese and cooked chicken breast. Enjoy!