For the last chicken I roasted, I used this recipe, slightly modified. The biggest modification was that I added liquid to the pan, it was eyeballed but let's say I used about 1/2 to 1 cup total of a vinegar/homemade chicken stock mixture...enough to come about halfway up the halved onions, in a 12" cast iron skillet.
After reading responses to this question about flipping the bird to get crispy skin, I had decided that some liquid in the pan wouldn't be a problem.
Turns out, when I took the bird out to rest and reduced the liquid (now with chicken drippings added), I was treated to the most delicious gravy I've ever had. It was like sweet liquid gold. I think the caramelization of the onions over the 2 hours was the main reason. I definitely want the same result, gravy-wise.
This time, I don't want to flip the chicken but I still want crispy skin, so I'm going to follow the recipe a little more strictly and not add any extra liquid to the pan and just baste with its own juices as they come out. However, I don't want to lose that delicious caramelized onion gravy.
So, my question: Will the onions still caramelize properly if they don't have a good amount of liquid around them to start? Or should I oil my skillet or add a small amount of liquid so there's something in there until the chicken starts to drip?
Also: Any other reasons for or against liquid in the pan that I might be missing?