The phrase "comfortable with doing" is correct and usable in written English.
You can use it when you want to express that someone is confident and familiar in performing a certain task. Example sentence: John is comfortable with doing routine maintenance on his car.
"I really need some time to feel comfortable with doing it," he said.
When a company is for sale, the investor willing to pay more is often comfortable with doing so because they have a close relationship with the CEO.
We understood that he needed to read it in the company of others to discuss these memories and become more comfortable with doing the interview.
As more people become comfortable with doing business by teleconference, business travelers will increasingly be able to say there's no place like home.
I tried to push the envelope a little bit in terms of what Puma has done in the past and also what they're comfortable with doing.
But I feel like my stuff has been crisp, and if they want me to do this, then I want to get back in there and I'm comfortable with doing it.
But surely in a good society both ethnic majorities and minorities should feel equally comfortable with - or indifferent to - their ancestry, history and myths (comfortable with does not mean uncritical of).
I don't know, it's difficult to know what's best for you, and we tend to do what we're just comfortable with, don't we basically?
Whichever way you feel comfortable with, do this that way.
Always behave in a way that you are comfortable with, don't let anyone pressure you into doing something you don't feel ok about doing.
If a popup shows up asking you to do something that you don't feel comfortable with, don't click on it.
