Set aside quality time for making this classic fish dish - perfect for impressive friends at a dinner party.
Preheat the oven to 180C/350F/Gas 4..
Lightly butter a shallow ovenproof dish. Fold the fish fillets in half and place in a single layer in the dish. Dot with pieces of butter.
Pour the fish stock and vermouth around the fish. Cover the fish with a piece sheet of buttered aluminum foil. Bake for 20 minutes, or until just cooked.
Remove the fish from the oven and carefully pour the cooking liquid into a large frying pan. Cover the fish with the foil and put back in the oven to keep warm.
Bring the cooking liquor to the boil over a high heat. Boil until reduced to around 100ml/3½fl oz liquid. Pour the cream into the pan and return to a simmer. Stir in the grapes. Cook for a further minute, or until the grapes are hot. Season with salt and freshly ground black pepper.
Remove the fish from the oven and gently pour over the sauce. Serve immediately.
