Melt butter over low heat.
Heat a cast iron pan over high heat, about 5 to 8 minutes.
Make sure the meat, poultry or fish is at room temperature and dry. Thin cuts do not work well. Dip the meat, poultry or fish into the melted butter and apply an even amount of rub to each side. Put into pan and leave alone for a minute or so, then check the underside of the meat for a nice dark crust. Adjust as needed. The kitchen may be quite smoky by this time. Turn the meat and repeat until the desired doneness is achieved.