First cook the fish by placing it in a lightly buttered shallow dish, add the wine and then cover the dish with cling film and microwave on high for 3-4 minutes (depending on the wattage of the oven). Do not overcook the fish as it is going to be cooked again in the pie; it should have an opaque appearance and flake easily. Alternatively you can poach the fish in a large pan with the wine over a medium heat. Allow the fish to cool in the stock.
When the fish is cooled, drain off and keep the stock, remove any skin and flake the fish into large pieces, divide between the 4 dishes along with the broccoli florets.
In a food processor or liquidiser, blitz the watercress with the Crème Fraîche or cream, add the fish stock and then pour over the fish filling in the dishes.
Roll out the pastry and use to top the four pie dishes, having first made a pastry ‘rim’ around top edge to ensure the lid does not fall into the filling. Brush tops with beaten egg and if desired sprinkle with sesame seeds. Bake in the oven for approx. 20 minutes until the pastry is golden brown.