Tolerance For Unbid Suits

Tolerance For Unbid Suits

N
W   E
 
S
K 10 9 7
5
Q 9 8 4
K Q 10 9

Dealer:

South

W N E S
1
Pass Pass ?

Partner may have a balanced hand with no biddable suit. She may be too weak for a 1NT overcall. She may have strong hearts (possible looking at our hand) and no biddable 5-card suit.

What should we call?