I'm always frustrated that pre-rolled and packaged puff pastry never has the cooking times and temperatures, they all blithely say "refer to your recipe", if you are like me, you often do not use a recipe!
Normal oven (Convection oven)
Set the oven to 200° C (400° F - gas 6) and bake in the middle of the oven for 20 minutes to 25 minutes. Check after 20 minutes as it's easy to burn the edges from cooking for too long.
Fan oven (Fan assisted oven)
Set the oven to 180° C and bake in the middle of the oven for 15 to minutes to 20 minutes. Check after 15 minutes as it's easy to burn the edges from cooking for too long.
Exceptions to this rule
Where the filling of the pastry is very moist or is cool and likely to lower the pastry cooking temperature inside the pie, the oven temperature should be the same, but you may need an extended cooking time of up to 40 minutes to ensure the pastry puffs up properly. Check regularly to ensure it does not burn. You can lay a sheet of aluminium foil on over any areas that look as though they may get over cooked. This will prevent them from burning.