"find challenging" is correct and usable in written English.
You can use it when you want to describe something as difficult to do or understand. For example: "I find the process of learning a new language challenging, but rewarding."
The whole issue of biking with children is one I find challenging.
But what many listeners still find challenging is the lack of discernible exposition and development, as in "Rothko Chapel".
Students can therefore spend a little longer working at their own pace on something they find challenging.
"What I find challenging as a practitioner is the lack of details from breaches, small and large" says Ford.
As the music plays, each woman falls gracefully into the routine, executing spins, twists and kicks that even a youngster might find challenging.
On the second day, we spoke for over an hour about how to keep them healthy and safe in their home and what daily activities they find challenging.
"What I find challenging about portraiture is that while each of us is just one of six billion people, no two are alike.
That means that Jay Y . Leeis taking over in an environment that even the most experienced manager would find challenging.
Against this, the United Kingdom and its European partners are following the maxim "small is beautiful" and are attempting to identify and develop academic research and commercial businesses in areas that traditional nanotechnology developments involving engineering or physics find challenging.
Before the exam, you should memorise and practise spelling words that you always find challenging.
Finally, planning experiments and working in a systematic fashion are processes students find challenging.
