The phrase "a matter on which" is correct and usable in written English.
It can be used when discussing a specific topic or issue that is being considered or debated.
Example: "This is a matter on which we need to reach a consensus before moving forward."
Alternatives: "a topic regarding which" or "an issue on which".
This is a matter on which honorable people can differ, and one way you can resolve it is to heed the wishes of local folks.
It is a matter on which we can find no law but our own prepossessions.
This isn't a baseless worry as it is a matter on which the government has previous.
They are not a matter on which he has advised the chair or panel".
In the end, this is not a matter on which Ms Sereny or any outsider can help much.
Campaign finance is a matter on which all members of the House of Representatives consider themselves experts.
Their current focus, on broadening the law, is aimed at a related matter on which they have amassed a great deal of anecdotal evidence: even employers that comply with the law find ways to restrict access to mental health care, by setting limits on the number of office visits or days of hospital care, as opposed to the dollar limits that the law governs.
After a few preliminaries – recollections of prewar Vienna, the Anschluss, parades, humiliations – we turned to a Viennese matter on which I needed assistance: deciphering an illegible signature scrawled on the back of an old Austrian photograph.
What they do with the rest of their time is a different matter, on which we couldn't possibly comment".
We are of opinion that the case is moot because, after petitioner's service of his sentence and its expiration, there was no longer a subject matter on which the judgment of this Court could operate.
The question of how one should live, what one's values should be, what is worthwhile and what is unacceptable in our relationships with each other, and what matters most in our conduct and our aims, is a vital matter on which everyone should reflect.
