"What I found quite interesting with this dish, being English," Mr. Oliver said, "is that when you eat this, it's quite delicately flavored. It's perfumed with the wine and the rosemary. You get this kind of meaty kind of saltiness from the olives…[w]hen you cook olives whole like this, it's almost like an anchovy. The salt comes out of the olives, and the olive becomes more like a vegetable. And the salt from the olive flavors the chicken really wonderfully."
There's also a special "interactive feature" with Hesser and Oliver, but I haven't watched it yet.