How to Make It
Put the skate in a large deep frying pan in one layer. Pour the water and the 1/2 cup vinegar over the fish. Add the thyme, 1 teaspoon of the salt, the peppercorns, bay leaves, and more water if needed to cover. Bring to a simmer and cook, partially covered, at a gentle simmer for 3 minutes. Raise the heat and bring to a rolling boil. Remove from the heat and let sit until the fish is just done, about 5 minutes. Carefully remove the fish and drain on paper towels.
Meanwhile, in a medium stainless-steel saucepan, melt the butter over moderate heat. Cook until the butter turns a medium brown, about 5 minutes. Remove from the heat and carefully stir in the remaining1 1/2 tablespoons vinegar, the capers, the parsley, the remaining 3/4 teaspoon salt, and the ground pepper. Serve the fish topped with the sauce.