Specialties often appear on the most expensive menu, or only on the carte.
Often they involve a surcharge if the ingredients are luxurious. At dinner we ordered the seasonal degustation and most expensive menu. It was superb and a great value, but expensive. A few years later we found ourselves eager to return, and decided to try the lunch special menu. It was less than half the price and inluded a bit of foie gras as I recall, but of course there were fewer plates and although the food represented the chef well, it was a far less spectacular meal.