1 (3-lb.) whole sheepshead or croaker, gutted, with scales, head, and tail left on
5 ½ cups kosher salt (about 3 lbs., or 1 box)
10 sprigs thyme; 5 left whole and 5 plucked of their leaves
10 sprigs tarragon; 5 left whole and 5 plucked of their leaves
4 sprigs rosemary; 2 left whole and 2 plucked of their leaves
6 dried bay leaves; 3 left whole and 3 shredded
1/2 lemon, sliced into thin disks
7 large egg whites
1 tsp. crushed red pepper flakes or pink peppercorns
Parchment for lining the baking sheet
Preheat the oven to 400°F.
Season the fish cavity with a half teaspoon of the salt and stuff with the whole herb sprigs, whole bay leaves, and the lemon slices. Whip the egg whites in a large bowl until frothy and add the remaining salt, whisking to combine. Chop the herb leaves and add them to the paste along with the shredded bay leaves and red pepper flakes; whisk to combine.
Lay the stuffed fish lengthwise in a baking dish or baking sheet lined with parchment and pat the herbed salt mixture over the fish in a quarter- to half-inch layer, until the entire fish is entombed (the tail can stick out, and it can be trimmed with scissors if it hangs over the edge of the dish).
Bake until the salt shell has browned nicely in a few places, 35 to 40 minutes. Crack the salt crust with the back of a large spoon, peel away sections of it along with the skin, and discard. Lift the top layer of meat off the bones with a wide knife or spatula, and pull the tail and spine upward to reveal the lower fillet once you’ve removed the upper one.
Place on a plate and serve immediately.