by All Weather Griller » 27 Jun 2010, 08:56
I have never done a topside I would have a tendency to grill that indirect Hot n Fast, so it's medium.
I normally hit something like that with 450Degrees F for about an hour and half then I'd let it rest a while before carving. It usually comes out rare to medium for me at the centre.
It all depends on size, and taste but I use a bit of wood for flavour.
Another tip, after a doing a couple of these now I have started to cook them in a foil tray to keep some of the juices, both for basting and for gravy.
Hope this is of use, I would check the cooking duration based on weight.