I get to whistler once or twice a year. My wife and daughter mostly control the restaurant selection. I just endure.
I'm a slave to burgers too. And pizza, and subs, and KFC, and... But I'm active enough to burn it off. I understand about trying different foods in different locations. If you're ever in Port Moody go to Pajos and get their fish and chips. Best on the planet. But I don't think Whistler really has a 'signature food'. They just have a bunch or refueling stations. I've been wracking my brains trying to think of one single memorable meal in Whistler, and I got nothing.