(to/with somebody) to begin talking about a subject that is difficult to discuss, especially because it is embarrassing or because people disagree about it (Oxford)
to begin a discussion of something difficult (Cambridge)
At some point we've got to discuss money but I don't know how to broach the subject with him.(Cambridge)
The report fails to broach some important questions. (Oxford)
how to broach the subject with him
report fails to broach
Bring up
Approach
Take back
Not mention
Broaching