I had started to use a cast iron griddle insert in my Weber grill to help get that awesome crust on my steak. On accident, I discovered that a "twice char" really does the trick. I like my steaks rare but it is hard to get that crust when you don't want to cook it long.
What I do is get the griddle insert as hot as can and just toss the steak on for about one minute to one and half minutes on each side depending on thickness and then I pull it. I let it rest while I cook the other people's meat. After it cools, I get the cast iron as hot as possible again, and I often use a blow torch to heat the cast iron to around 700. Drop the steak back on it for another minute to one minute and a half on each side.
The crust from being seared is awesome and does not taste burnt at all. The best ribeyes I ever had were made by this method.
Here is an example.