You can tenderize a cut of beef by pounding it with a meat mallet. If you don't want to go to that much trouble you can add a teaspoon of white vinegar to the liquid when you prepare the meat and it will come out tender every time.
I believe stores sell meat tenderizers in a powder form that you can sprinkle on your meat, but I have found that the best meat tenderizer is a large mallet.
