if it's just a small one which will be re-potted later, then any multi-purpose compost. If it is something that will remain in a large pot for quite some time then a peat-based compost mixed with John Innes soil-based compost No.2 or 3.

I put mine in jI no 3 from the off and then top dress with gravel to reduce the chance of vine weevils laying eggs in the pot.

Thank you Jimmytheone and Seaburngirl,thats a great help.Callie