from John Ondo of Lana in Charleston, South Carolina
4 grouper fillets
2 tablespoons rendered fat or vegetable oil (lard works great)
Salt and pepper to taste
Heat grill to medium high (about 425 degrees). Have coals centered and close to the grate. Place a 10-inch cast iron pan directly over the coals and let it get hot about 4−5 minutes.
Season the fish with salt and pepper. Add fat into the pan and place fish in the pan. Close the lid and let them cook on one side for about 5−8 minutes, depending on thickness. When the fish is somewhat firm to the touch, it is done. Flip the fillets and immediately remove from the heat. Let fish rest a few minutes in the pan and serve.