SWAG: A utensil for frying, but frying what, I don't know.
If it were for boiling, it likely wouldn't be cast iron due to its weight. Because it's cast iron, I say it's for deep frying. What I don't know is what might need to be encased like this when it's fried. Most things cooked in deep fat form a crust that holds the item together. What, when placed in deep fat, falls apart but needs to be kept together?