XML : python xml etree get all subtext of element

I have an xml document like:

  <root>   <el> rawr    <p> blah blah <b>important</b> blah blah </p> what   </el>  </root>    

I need to extract the string:

  'rawr <p> blah blah <b>important</b> blah blah </p> what'