Castacán is the Yucatecan version of crispy pork belly. These tacos are crisped up on a griddle, then topped with shredded cheese. As the cheese melts, it oozes into the spaces between the meat, binding the bits of pork belly together. The whole thing sizzles until the cheese is browned and crisped.| Serious Eats
Sope shells start with a dough made from masa harina (that's dehydrated nixtamalized corn flour) that gets flattened into a thick disk. The edges of the disk then get pinched to form a shallow saucer. The raw sope shell is fried just long enough to get it to hold its shape, but not so long that it gets crisp. The idea is that you want it to form an impenetrable barrier for the treats that go on top of it, but you still want it to be soft and warm in the center.| Serious Eats