Sorry, just went back to the thread. I use tenderloin or back strap sliced thin against the grain of the meat. I marinade it for 3 to 4 days. (Will have to find the mix when I get home, it is lengthy and numerous items but works good) Drain marinade. I then add olive oil in skillet at about 3/4 heat on burner, put in meat and sear the meat at high heat just for about 2 to 3 minutes until it starts to brown a little, stirring continuously. Reduce heat to medium, add sliced red and green bell pepper, sliced red onion, about half a can of Rotel, Worcestershire sauce, liquid smoke and course ground pepper. Cook till vegis start to go limp. Reduce heat to low and add about a quarter stick of butter until butter is melted. Then it is time to eat. Unbelievably tender! I had them with frozen margarita.