Run a modern car (2010+ model) until all parts, oil and coolant has fully reached operating temperature. After driving for some time, shut it down at the gas station and leave it off while refueling (less than five minutes) and restart it. How long does it take for the engine to fully regain oil pressure? Is it ok to rev it quite hard after a minute or so?
A normally operating engine regains pressure almost instantly. Oil residual stays in the bearings and on parts for quite some time after the engine is turned off.
As soon as the engine starts turning the oil pump pressure begins to build. This only takes a second or so.
Unless there is something wrong with the engine, or the oil pump, I doubt there would be a lack of sufficient oil pressure to prevent you from revving the engine after a minute of running.
Note: this is a very general answer to a very generalized question. If there is some specific issue you are having, please add details to your question.
Oil pressure may be built up within engine bearings but it does not mean that all components that use oil have sufficient amount such as hydraulic lifters and some timing belt tensioners so I would let it idle for a few seconds before revving the motor, no matter how short of a time span the motor had been off.
Also, I don't understand why you want to "rev it quite hard", are there other issues that need to be addressed?