I cooked a whole duck a few weeks ago for the first time. Interesting to say the least... in my experience it's been one of the more difficult birds to cook whole, just 'cuz it's a bit different that chicken or turkey.
I split it in half and cut out the spine. Salted each half and left uncovered in the fridge for a few hours. Heated up two big steel pans on medium - not too hot - and laid each half skin side down in the pan to render some fat and crisp the skin. When the skin was crisp-ish and a good amount of fat was in the pan, I flipped the bird and added onion, carrot and sweet potato. Put the bird on top of the veg. In the oven at 300 for a while, until all was gently cooked through.
The results was good but not stellar. Sweet potato wasn't a good choice, but it's all I had on hand atm, and they turned soft and mushy. Carrot and onion were fine. Everything absorbed a lot of duck fat, so they tasted awesome. The breast meat was a bit dry, not like shoe leather, but drier than I prefer. The leg meat cooked well, but still a bit dry. And there's a lot of bin in duck compared to what we're used to in a chicken - not nearly as much meat as a similarly sized chicken. But that's how chickens have b
I think the best approach may be to quarter the bird and treat the legs and breasts separately. Duck breast is best medium rare, and leg needs a good low and slow, hence the confit.
I'm sure some other guys have more experience with whole duck, but I found it a tricky one. Definitely need to play more with it.
(I also did a couple of turkey wings that were left over from Thanksgiving).