Nurse shark has tough meat that isn't widely eaten or often found in markets. If you do find nurse shark steaks or filets and want to try them -- they'll probably be quite affordable -- or if you catch and clean your own nurse shark, the meat may be prepared like more common types, such as mako and thresher sharks. For the best results, though, begin with a dairy-based marinade that tenderizes the meat and helps temper strong fishy flavors.
Fill a baking dish with enough milk, buttermilk or yogurt to cover the nurse shark meat. Add salt, pepper and the rest of your seasonings to taste; cayenne or another spicy pepper powder, cumin or rosemary works well.
Place the shark steak or filet in the marinade. Cover the dish with plastic wrap and put it in the refrigerator. Marinate the shark for about 30 to 60 minutes. Turn it over once halfway through the soak time to ensure complete marination.
Remove the nurse shark from the marinade, let the excess run off and blot it dry with paper towels when it's time to cook. Season it with salt, pepper and additional herbs, spices or aromatics. Discard the marinade, as it's been contaminated by raw seafood and dairy doesn't boil and reduce well to sterilize and use as a sauce.
Preheat the oven to 375 degrees Fahrenheit for about 20 minutes. Line a baking tray with parchment paper or foil lightly greased with nonstick spray.
Place the nurse shark meat on the baking tray and put it into the middle of the oven. Bake it for about 20 minutes.
Transfer the steak or filet off the baking tray as soon as the flesh is opaque all the way through and it's cooked to an internal temperature of 145 F at the center. Use an instant-read food thermometer to measure doneness.
Turn on your oven's broiler about 10 minutes ahead of time to preheat. Lightly grease the rack of your broiler pan with nonstick spray.
Place the nurse shark on the broiler pan and insert it into the oven so the surface of the food is 4 inches directly below the broiler.
Broil the steak or filet for 5 minutes, then turn it over. Cook it for another 6 minutes or so, until the meat is uniformly opaque inside and has reached an internal temperature of 145 F.
Clean the grill and grease it with nonstick spray. Preheat to moderately high heat.
Lay the cut of shark meat presentation-side down on the grill, angled so the grill marks sear diagonally across the flesh. Rotate the steak or filet 90 degrees after about 2 1/2 minutes if you want to sear in a crosshatch pattern.
Flip the nurse shark after grilling the first side for a total of 5 minutes. Continue cooking it for about another 6 minutes. Remove it from the grill once the flesh is opaque and the internal temperature reaches 145 F at the center.