The phrase "a subject of such" is correct and usable in written English.
It can be used when referring to a topic or matter that has been previously mentioned or is understood in context.
Example: "The committee discussed a subject of such importance that it warranted immediate attention."
Alternatives: "a matter of this kind" or "a topic of this nature".
A subject of such importance requires something much bolder.
Kochan later attacked the "Holocaust industry" and sparked rancour by arguing that only experts should deal with a subject of such sensitivity.
Jihadi John became a subject of such fascination that some children started to mimic his uniform, he said, wearing all "black and a belt with a little knife".
And there is meditation on the tough, bereft melancholy of Russia and its peoples, a subject of such high romanticism that it is always threatening to topple over into cliché or camp, and yet somehow it never does.
It is interesting to observe the fusing of Hardwick's sumptuous style with a subject of such elusive grandeur, but the innumerable expressions of pure devotion take up valuable room in a short book.
Coppola, speaking with Griffin about "Apocalypse Now," said that the Vietnam War was a subject of such intrinsic importance that he made sure "that it would be beautiful and that it would in some way throw light on the subject".
The idea that God must uphold his end of the first commandment has been a subject of works such as Elie Wiesel's play The Trial of God (1979), made in response to the atrocities Wiesel witnessed at Auschwitz.
As a veteran subject of such reporting, I am quite comfortable with the general nature of these items.
I have never had a client be the subject of such an unrelenting public scrutiny and focus.
Ghomeshi's lawyer Marie Henein told the court she's never "had a client be the subject of such an unrelenting public scrutiny and focus".
The ballet world, like the fashion world, sets wildly unrealistic standards for what a woman is supposed to look like -- although perhaps only in Russia could a dancer's weight become the subject of such a frenzy of national gossip.
