I am not about to explain how to cut this chicken to make it this flat...so please visit Jen's blog where her husband Dietsch elucidates and sends you to Gourmet for the how-to. It's easy to do, but best explained in pictures.
The result is perfect skin. Now roast chicken with crisp skin is not hard to achieve (one hour, 450 degrees), but with this flattening, run-over method, ALL the skin is crisp. There is no down- under that sits in the juice and stays soft.
It's a little upsetting, I grant you. The breast out there on its own...but it leaves all the best bits - in my opinion - in one piece, and the breast for something else, the next day. And you have all that Peking duck-like skin to crackle between your teeth.
I put a handful of terrace herbs (tarragon, thyme, parsley, summer savoury) under the bird while it roasted, as well as a shallot, which does wonders for the perfume when it cooks. Deglazed the pan with some water and Vermouth...