Starting a command in the background

As part of one of our builds we require a X server running. I'm trying to start Xvfb however when I'm adding this to job as a command or script it hangs and waits for Xvbf to finish instead of going onto the next job in the stage.

How would I be able to start Xvbf in the background and let the Job continue?

I've tried using &, && in a script. When using it as a command I can not as this is not a valid argument to Xvfb. Am I missing something? Is this possible?