Tiling with an obstruction

[stan4th]

Hi,
we have had the walls plastered ready for tiling - but there was a problem.
The wall to be tiled had a capped pipe protruding and the workman had hammered it round thinking he could completely push it so the plasterer could cover it.
Its 5-10mm but I wonder whether there are any clever tricks to successfully tiling over this.
Any ideas please?