The phrase "a growing mastery of" is correct and usable in written English.
It can be used to describe an increasing level of skill or proficiency in a particular area or subject.
Example: "Her dedication to practice has led to a growing mastery of the violin, impressing both her teachers and peers."
Alternatives: "an increasing proficiency in" or "a developing expertise in".
Ms Messud's writing shows a growing mastery of mood.
It is true that creative work in any field involves a growing mastery of skills and concepts.
I have a similar problem with Twombly's later invocations of gods and goddesses, charged with rather fey, private meanings — a fault only partly offset by a growing mastery of harshly eloquent color.
Opener Harborcoat demonstrates a growing mastery of the studio - Peter Buck's almost formal playing on the verses giving way to sheets of harmonies and guitars on the chorus; So.
And whatever his flaws as a novelist, his growing mastery of the short-story form continued to define him as a writer.
Drawing heavily from the archives of the Royal Navy, a historian chronicles Britain's growing mastery of the seas, which was essential to the nation's survival, and provides copious detail on strategy, ship design and the officers and men who served the crown.
Henry's volte-face was probably motivated by a desire to retain dominance over Normandy, which was now threatened by William's growing mastery of his duchy.
It is indisputable evidence of China's growing mastery of military technology.
He says he feels more independent, thanks to the cane and his growing mastery of Braille.
At the end of the day, his own involvement in contemporary religious controversy and his growing mastery of Latin sources drew him almost irresistibly toward Rome.
Crescendoing from totally mundane music video concepts to actual surreal, semi-frightening 3D experiences, the six-piece series shows the artist's growing mastery of this burgeoning technology.
