ASDA part of the Wal-Mart family

• 50g butter
• 50g plain flour
• 600ml semi-skimmed milk
• 142ml single cream
• Squeeze of lemon juice
• 85g bag Asda watercress, roughly chopped
• 450g smoked haddock fillet, skinned and cut into chunks
• 100g white fish fillet such as cod or haddock, cut into chunks
• 340g block frozen puff pastry, thawed
• 1 egg, beaten, to glaze

1 Preheat the oven to 190C/Gas 5. Melt the butter in a large saucepan and add the flour. Cook, stirring, for 1 minute then remove from the heat. Gradually stir in the milk. Return to the heat and bring to the boil, stirring until thickened.

2 Stir in the cream and lemon juice and season. Stir in the watercress. Place the fish in an ovenproof pie dish and pour over the watercress sauce.

3 On a floured surface, roll out the pastry to the thickness of a pound coin, large enough to cover the dish. Brush the edge of the dish with a little egg and place the pastry over the dish. Trim the edges. Make a small hole in the centre to allow steam to escape, then brush with the egg. Bake for 35 minutes until the pastry is crisp and golden.