<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def build_and_start(query, directory):
 """This function will create and then start a new Async task with the default callbacks argument defined in the decorator."""


    Async(target=grep, args=[query, directory]).start()