Stewed Skate with Caper Sauce

Wash and clean a skate, place it in a saucepan with one sliced onion, a bunch of
green onions, two bay leaves, and a small bunch of parsley and thyme; cover the fish
with water, add a small quantity of vinegar, season with pepper and salt, and stew it
gently until tender. When cooked drain the fish, place it on a hot dish, cover it with
caper sauce and serve.