Rinse the skate and place in a pot. Cover with cold water and add the fish stock cube. Bring to a boil and then simmer for 15 to 20 minutes depending on the thickness of the skate. Cool the skate and remove. Trim the edges of the skate wings with scissors and remove the skin, if any. Divide the skate into portions and place on a serving platter. Keep warm. Cook the butter until it turns nut brown. Off the heat slowly add the vinegar and same amount of strained stock, plus the capers. Boil and pour over the skate. Sprinkle with parsley and serve with steamed potatoes and slices of lemon.
