Await with sync method.

[cicatrix]

Hello, I'm trying to sort the things out with the new multithreading model using the await and async keywords.
Now I have a project where I have a lengthly method that I'd preferred to call asyncronously:

private void StoreData(List<string> data)
{
   ...
}

Now, I want this method to be called both syncronously and asyncronously depending on certain logic.
I've made another method

private async void StoreDataAsync(List<string> data)
{
   await ... // ???
}

Now, what should I put into the StoreDataAsync to call the StoreData logic asyncronously?
I certainly can make it work using the old multithreading model, but is it possible to make it work the way I described?