Gotta be a tie between a pork belly dish at Tiffins(it was like a year or 2 before covid hit) and the ceaser salad at grand floridian cafe.
The pork belly was literally no meat(I know pork belly is supposed to be fatty, I LOVE fat when cooked properly. I even eat the eye of fat on prime rib and the big chunk on the end if they give it to me) and all fat. And it was so undercooked the fat was still white and chewy. So I got noodles with chunks of chewy undercooked blubber and no meat. Couple that with having to hear about this "innovative" sous vide technique on the octopus (sous vide is not innovative, its not 2002) and I was not having the best time. I tried Tiffins 5 times since it opened and never had a good experience or service. And AK is my favorite park, which is why I desperately want to like its signature dining and keep going back
The ceaser salad at grand floridian Cafe tasted like Romaine dipped in water with cheap parmesan on top. Just so bland its kind of shocking. Absolute flavor vacuum. (The Wave had a great ceaser btw, can't wait to try the version at steakhouse 71 in december!)
The other stuff I have had at Grand Floridian cafe was fine btw, I'm not saying the whole place is bad. But that salad is an atrocious execution of a countrywide staple.
Gasparilla's at the Grand Floridian had the best mac and cheese 2 years ago. I loved it so much I ordered it multiple times on that trip. Went back a few months ago and was excited to order the mac and cheese again- it was the most vile concoction- tasted like warm pasta mixed with mayonnaise and a hint of cheese, so disappointing and the worst thing I've ever eaten at Disney.