Ingredients 4 large sole fillets, skinned
2 tbsp lemon juice
50g ricotta cheese
300ml fish stock
4 black olives, stoned and halved
1 pickled gherkin, chopped
For the Tomato Sauce 25g butter
2 tbsp olive oil
1 onion, finely chopped
2 garlic cloves, finely chopped
1 celery stick, finely chopped
2 tbsp tomato puree
1 tbsp brown sugar
1 tbsp chopped fresh flat-leaf parsley
First, make the sauce. Melt the butter with the oil in a saucepan. Add the onion, garlic and celery and cook over a low heat, stirring occasionally, for 5 minutes, until softened.
Stir in the tomato puree, sugar, parsley and water and season to taste with salt and black pepper. Increase the heat to medium and bring to the boil, then reduce the heat and simmer, stirring occasionally, for 20 minutes, until thickened.
Meanwhile, preheat the oven to 200C. Season the fish with salt and black pepper and sprinkle with the lemon juice. Lightly beat the ricotta in a bowl with a fork until smooth. Spread the mixture over the strips of fish and roll up.
Put the rolls into an ovenproof-dish, seam-side down, in a single layer. Pour over the stock over them and bake in the preheated oven for 20 minutes, until the fish flakes easily.
Using a splotted spoon, carefully transfer the fish rolls to a warmed serving dish. Spoon the tomato sauce over them and sprinkle over the olives and gherkins. Serve immediately.