That's a common way Pacific Northwesterners do salmon. When you have the fish trimmed, leave the head on and the dorsal fin. Fill the cavity with green onions, carrots, seasoning, etc., on foil. Add some white wine and wrap it up with the foil in such a way that you can get to the dorsal fin easily. You can cook it on a barbecue grill or in the oven. When you think it's done, tug on the dorsal fin. If it pops out easily, it is done.
Be sure to eat the cheeks — they are the best part!