Heat a large frying pan and a large saucepan. Fry the guanciale until golden brown. Then add the barley and cream. Season with pepper and add the cheese.
Cook the fish seasoned skin side down and then add butter, thyme and water to finish the cooking. Add the sea samphire near the end. Cooking of the fish takes 5-8 mins.
Serve up on nice warm plates with the fish sliced and enjoy.