Once the flat rock is hot, cut a few pieces of fat and throw them on. The fat will melt, giving you a nice slick of grease to fry on. Cut your meat in fairly thin pieces, and they will cook quickly. There are a couple big advantages to this method. For one, the meat doesn't dry out like it tends to do over an open fire, getting scorched on the outside and remaining raw on the inside. It's just like pan cooking a steak, the meat will cook in its own juices. Second, it's a very clean cooking method, and you won't have to worry about scrubbing your pan afterwards. Sheep meat, especially, leaves a grease on the pan that is very frustrating to try and clean, and still manages to get on everything.