He is more than capable of (doing it)
He can do it with ease.
He can do it blindfolded.
He can do it with one hand (or both hands) tied behind his back.
This job is a piece of cake for him.
This job is a no brainer for him.
a piece of cake seems not that appropriate, I'm looking for a more professional phrase to express.....Acutally , i even thought of an ace in the sleeve but still not to the point !!!! thanks anyways !!