The phrase "a daunting task of" is correct and usable in written English.
It can be used when describing a task that is intimidating or challenging in nature.
Example: "Completing the project on time felt like a daunting task of immense proportions."
Alternatives: "a challenging endeavor of" or "an intimidating job of".
Chris Adcock has set himself a daunting task of qualifying for both the men's and mixed doubles badminton tournaments.
He has spent his summer pursuing a daunting task of reassuring the French that the economy will exit from recession.
The court recognized that the state had a daunting task of providing so many educational improvements in so many districts in such a short time.
Libya's new leaders face a daunting task of establishing security, restoring public services and balancing regional and tribal interests in an inclusive government.
By Tuesday, Aug. 30, with the levees broken and the city underwater, 13 hospitals were facing a daunting task of evacuating patients, staff, family members and people who had taken shelter inside.
Military searchers face a daunting task of trying to find evidence of an airplane that could be at the bottom of the sea anywhere in thousands of square miles of open water.
What would be a daunting task for most of us is, for Georges Lopez, the application of a natural gift to a highly rewarding purpose.
Challenging Woods for golf supremacy will be a daunting task for any of these players.
Learning the students' names is suggested as a way to foster instructor-student relationships, but can seem like a daunting task for instructors of large classes.
Guessing two good initial outer approximations would in general turn out to be a daunting task for systems of nontrivial dimension.
Here is a typical hole: Now this is a daunting task for any of us 20 feet (6.1 m) away or more, especially with such a small target.
