Preheat the oven to 180C. Using a sharp knife, cut the plaice fillets in half lengthways to make eight smaller fillets.

Melt the butter in a pan and cook the onion and celery. Cover with a tight-fitting lid and cook over a low heat for about 15 minutes until softened. Do not allow to brown.

Mix together the breadcrumbs, parsley, pine nuts, sun-dried tomatoes and anchovies. Stir in the softened vegetables with the buttery juices and season to taste with pepper.

Divide the stuffing into eight portions. Taking one portion at a time, form the stuffing into balls, then roll up each one inside a plaice fillet. Sauce each roll with a cocktail stick.

Place the rolled-up fillets in a buttered ovenproof dish. Pour over the stock and cover the dish with buttered foil. Bake for about 20 minutes, or until the fish flakes easily. Remove the cocktail sticks, then serve with a little of the cooking juices drizzled over.