“a restrained way” is correct and usable in written English.
It is often used to imply that something was done with caution or with careful moderation. For example, “She spoke in a restrained way, ensuring that her opinion was heard without offending anyone.”.
I smiled in a restrained way.
Judging from the behavior of many of those in trouble, the most popular course is to behave as if things were normal, though in a restrained way.
"Some trees will be cleared to provide a view of the mansion from Asylum Avenue," said Robert Emma, "lighted in a restrained way at night".
He is consequently unwilling to speculate on the drivers that might make a pin-up out of Noel Fielding, though he does point out, in a restrained way, "Back in the Pleistocene, Bill Gates may not have been as successful as he is now".
While angered by Taylor's manner, the officers defended themselves in a restrained way.
The sour cream and cheese made their presence known, but in a civilised, restrained way.
In "The Making of the President 1972," Theodore White quotes McGovern saying, "I can present liberal values in a conservative, restrained way..
He plans to show his fall collection during Fashion Week, at 9 a.m. on Feb. 15, in a more restrained way.
In "The Making of the President 1972," Theodore White quotes McGovern saying, "I can present liberal values in a conservative, restrained way...
The only difference at the time between the so-called quality and the popular press was that the upmarket titles carried the same gossip in a more restrained way.
What is a fact is that the BBC presents information on the obnoxious policies of this vicious government in a remarkably restrained way, considering how it is required to report on the indefensible, day after day.
