Rinse the fish and pat dry; season it inside and out with salt and pepper. In a mixing bowl, combine the lemon, shallot, parsley, 2 tablespoons thyme, bay leaves, red pepper flakes, and 1/4-cup olive oil. Place the fish on an oiled baking sheet and stuff the cavity with the lemon mixture.
In a clean mixing bowl, whip the egg whites until they form soft peaks. Fold in the salt to make a paste then fold in the remaining thyme leaves. Smear the salt paste over the entire fish and roast for 35 to 45 minutes. The egg whites will form a hard crust. Gently crack the shell with a spoon and lift off the salt crust. Serve.