Preheat the oven to 200 degrees C. Put the flour in a bowl and rub in the spread with your fingertips until the mixture resembles fine breadcrumbs. Stir in the cheese and chives, then add enough cold water to bind to a dough. Wrap in plastic wrap and chill, while you make the filling.
Heat the stock in a large saucepan until boiling, then add the broccoli, leek, beans and peas. Bring back to the boil, cover and simmer for 5 minutes. Drain, reserving 300ml of the stock.
Divide all the vegetables among four 350ml pie dishes. Mix the cornflour with the water and stir in the reserved stock. Pour into the pan and stir over a medium heat until thick and smooth. Add the parsley. Pour over the vegetables.
Roll out the pastry and cover the pie dishes, sealing the rims with a little water. Cut a small vent in each pastry lid. Place on a baking tray and bake for 20–25 minutes until the pastry is firm and golden brown. Serve hot.