When thawed, marinate it -if only briefly, and grill, broil or pan-sear. A good marinade is soy sauce and a can of crushed pineapple, possibly with a little olive oil. If you don’t have pineapple, some lemon, lime, or any citrus juice is a good idea. Shark can have a kinda tough texture if you don’t use an acid in a marinade to do a preliminary break down of some of the cells. White wine or pickle juice if you don’t have pineapple or citrus. Butter if you don’t have olive oil. Maybe some red chile or a little garlic in the marinade. Shark takes additions of flavor well. If you are of a mind to grill, grill hot and keep an eye on the shark. If you don’t have a grill but like the little lines that get branded into grilled food, heat up your oven hot, put a big shallow or flat pan on the bottom shelf and plop the marinated shark straight onto the top shelf. Flip the shark as you would on a grill.
There are other things you can do with shark – marinate in coconut milk and Thai spices, for example, but that’s for a very specific flavor mood. Shark can be used in shish kebabs. It also makes pretty good Baja style fish tacos.