Prepare the puff pastry using the previous recipe (unless you’re using the ready-made variety) and return it to the fridge.
Heat the oven to 220°C/gas 7. Roll out the pastry to 30cm by 40cm and cut into 6 equal-sized pieces. Using a fork, make indentations all over the base (this helps to keep the pastry flat when cooking). Cut a 5mm strip from around the edge of each piece, brush the edges with beaten egg and lay the thin strips back on the pastry base, like a picture frame. Work the edge of the pastry by gently marking each edge with horizontal indentations using a fine-bladed knife; this helps the pastry to rise and form a neat edge. Place on a baking sheet, put it into the oven and cook for 12-15 minutes until golden. Remove from the oven and reduce the heat to 180°C/gas 4.
Melt the butter in a large pan, add the shallots and fry gently for 5 minutes without browning. Add the garlic and mushrooms and fry for a further 4 minutes, stirring frequently. Return the pastry cases to the oven for 4 minutes. Add the wine and cream to the mushrooms, increase the heat and simmer for 1 minute. Season and add the parsley. Spoon into the cooked pastry cases and serve at once.