Star laughing about Ed Gamble's opener (3,5)

I haven't cracked this one yet — but the brilliant team at Times for the Times have:

You don’t need to know this, but Ed Gamble is a regular on the soon-to-be-revived Mock the Week (hurrah!) and similar comedy shows. All you need here is the ED and the first letter of Gamble, wrapped in RIANT for laughing.