"ostentatious way" is a correct phrase and can be used in written English.
It means a showy or flashy manner of behaving or doing something. Example: She entered the room in an ostentatious way, adorned with expensive jewelry and designer clothes.
It was the most ostentatious way and everyone knew she appreciated that.
Also brilliant: the ostentatious way Escobar chucks around his cash around.
Nigel Farage asserts that breastfeeding mothers should "sit in the corner" rather than feed their babies in an "ostentatious" way.
To see his image on Ms. Midler's stage was to notice, for the first time, the brightness of his cardigan, the ostentatious way he changed his shoes.
And I also get that this is a smashing way for the food industry to persuade the ignorant middle classes to part with their cash in a pleasingly ostentatious way.
Mr. Menem has cast a long shadow over Argentina since his election in 1989 when he burst onto the political scene with his mutton-chop sideburns, zest for fast sports cars and ostentatious way of life.
Lots of ordinary families live around here, but there are also wealthy people without boundaries, whose peculiarities flourish in ostentatious ways.
She was always elegant in an understated, non-ostentatious way.
The range of Generic Man shoes, from double monks to creepers, offered non-ostentatious ways to get in on any of the last few waves of men's footwear movements.
On the other hand, Dr. Sloper has an almost puritanical work ethic, and there is a kind of dryness about him and a lack of flamboyance that suggests that the house not be overly embroidered or ostentatious in any way.
The question is, then, if basic decorum is out the window because a re-election campaign is more or less out the window, and Trump can be expected to, with ostentatious grace, make way for his veep Mike Pence what else will go by the wayside?
