i'm not exactly sure what they were thinking to make it to 7C, they were scared of the two singletons or perhaps a bad split in clubs if you only hold 2. You have A of clubs, opposite king, queen...TEN, no jack, so no 7NT I guess. However, in 7C, you have the same problem with the split, so in honesty, I haven't a clue why they would not be in 7NT, lol. So only way is to go slower, ask for kings, find 7NT, but I think even if partner showed 1 or 2 kings, I may still give it a try, he opened 2NT and shows 20-21, with his 3 aces, he has only shown me 12 of his points, he has 8-9 somewhere, so if he shows no kings, I know he has to have 8-9 in the rest, which is very likely to be the J of clubs (great!) or the Q of diamonds.