It’s always nice to be dealt a good hand.  It’s even better to get a good hand and hear partner open the bidding.  Here’s one of those happy times.  You, East, are dealt:

S) 2
H) Q 8 2
D) A Q 7 6
C) A K 7 6 2

Nice hand - 15 high-card points.  Not quite so nice after partner opens 1S.  This may not be so easy after all.

This was a deal from a recent world championship scored in IMPs (international match points - somewhat closer to rubber than match-point duplicate scoring) and it proved to be too much for some pairs.   Two pairs found a fit in clubs and went to slam with two quick losers in hearts.  The worse case was when East (your hand) responded 2C and the opponents entered the bidding, sacrificing at three diamonds doubled and making.

Back to you.  What do you say after partner opens 1S?  The natural and popular choice seems to be 2C.  But why bother?  You have the values for a game in notrump, which is certainly equal to or better than a game in clubs.  My choice is to bid 3NT directly.  It accurately defines your strength and denies spade support.  Are you likely to miss a good slam?  Certainly not if it is playable in notrump.  If you don’t call notrump immediately, there is a good chance of missing the best contract.

In the world championship, only one pair contracted 3NT and they scored the highest points.  The full deal:

                          North
                          (S) Q109873
                          (H) A84
                          (D) 832
                          (C) 10
West                                                 East
(S) AKJ64                                         (S) 2 
(H) J9763                                          (H) Q82 
(D) --                                                 (D) AQ76 
(C) QJ5                                             (C) AK762
                           South
                          (S) 5
                          (H) K5
                          (D) KJ10954
                          (C) 9843