Having just picked up my first kettle grill last week, I have not had the opportunity to try using my CI on the kettle grill itself, or even cooked a good steak on the kettle for that matter. My first ever cook on the kettle last week was a chimichurri marinated skirt steak. Looking forward to a nice rib eye or porterhouse on the kettle soon.
However, we all love the reversed seared steaks I cook using my pellet smoker, and then searing in a CI skillet on my gasser side burner. I use a little butter, or even better ghee, when searing in the CI. The last picture I took after taking the steak off the outside burner and bringing it inside to eat. It was not seared on the stove as it would appear in the picture.