Here is how my partner and I would bid this: South opens 2 ♣, intending to bid the Diamonds. North responds 3 NT. South considers slam in NT and sees 6 NT easily. But he also sees a possible grand slam in ♦. His hand has more value with a fit in ♦. So he proceeds with his plan and shows his ♦. He bids 4 ♦. North has a fit in ♦. He can see the slam in ♦, but he can also see the possibility of a grand slam in ♦. He considers Blackwood, but he has a worthless doubleton, so he raises the ♦, knowing partner will not pass. He bids 5 ♦. South sees the possibility of a grand slam in ♦. Blasting to 7 would be easy but reckless. There is no rush. He bids 5 ♥, showing that Ace. North's worries with his worthless doubleton are resolved. He can see the grand slam possibilities, but he has no Kings at all. So he bides his time with a bid of 5 ♠, showing that Ace. South sees 3 Aces. Does North have the ♣ Ace? He cannot be sure. He knows it's clear to both partners that they are looking at 7 ♦, so he bids 6 ♦, indirectly asking about the only suit that hasn't been discussed - the ♣. North has the ♣ Ace. He bids 7 ♦. South sees solidity everywhere. He can see four Aces and four Kings. It's likely the ♦ will run for five tricks. He bids 7 NT. The key is the super-positive first response by North which locked up the minor slam and allowed room to investigate 7.