You and partner pass and the opposition bids to 3NT - All pass
Acol Bidding
You and partner pass and the opposition bids to 3NT - All pass
Plan Before You Play
Lead your diamond suit KD then AD then a low diamond hoping to exhaust declarer's stops in diamonds making your low diamonds into winners if you get a second chance to lead.
The Play
After leading the diamond suit 3 times the opposition lose to your KH while trying to establish their heart suit - you then play your last 2 low diamonds and have already defeated their contract.
Comment
The opposition have two possible optimum contracts with their 27 points. If you lead your Diamond suit they cannot make their contract either the 3NT or 4H. If you lead your longest and strongest suit continuously whenever you have the opportunity they will not make their contract. You make 5 tricks.
The above commentary is intended as a guideline only. As with any Bridge hand there are many ways to bid and play any hand.