Rinse the lamb meat properly, and simmer in an earthenware casserole dish or in another pot. Skim the foam off and drain the water. Place the boiled meat into casserole dish. Put two large slices of tomato and a few pepers onto the meat. Add half a tablespoon of butter. Add a proper amount of water of the meat, put the casserole dish into the oven and bake. Put the casserole out of the oven after the meat turns brown and serve the dish.