OVER-REVVING ON COLD STRT

I have this problem that is worrying me. Whenever I start the car from cold the engine (2.7 V6) races up to over 2000 RPM in a split second then drops back to a sensible tickover around 1000 RPM.
In its initial spurt I can hear what I think is a bearing knock before the oil pressure has built up. It only lasts a couple of seconds at most.
I was always taught the you should never rev a cold engine and better still you should let it warm up a bit before moving off.

My question is, what can be done to prevent this revving which I think is harming the engine? I expect it to start and run at 1000-1100 RPM at the absolute maximum when cold.
In addition to this when I so much as breathe on the accelerator pedal it's sets off like a rocket but then calms down.
Once it has warmed up it behaves normally.