Method

1. To make the fishcakes, mix together the potato, half the poached salmon, the ketchup, anchovy essence, mustard and seasoning, until evenly combined.

2. Fold in the rest of the salmon. Mould the mixture into 8 round cakes and refrigerate.

3. For the sauce, bring the fish stock to the boil in a thick-bottomed pan.

4. In a separate saucepan, melt the butter and stir in the flour. Cook very slowly over a low heat for 30 seconds, then gradually whisk in the fish stock.

5. Pour in the white wine and simmer gently for 30 minutes until the sauce has thickened.

6. Add the cream and bubble the sauce for a further 5 minutes or so, until it is a thick pouring consistency. Stir in the sorrel and season to taste.

7. Preheat the oven to 200C/gas 6. Dust the fishcakes in flour.

8. Heat the oil in a frying pan and fry the fish cakes for 2-3 minutes on each side, until golden. Transfer to the oven and bake for 10-15 minutes.

9. Heat a large saucepan over a medium heat and cook the spinach for 3-4 minutes until just wilted. Drain in a colander.

10. Divide the spinach between 4 plates and top with the fishcakes. Pour over the sauce and serve straight away.