For the Steak & Marinade: In a large bowl whisk together all the marinade ingredients, add the Beef Tenderloin, spoon the marinade over the meat, then cover with plastic wrap. Let marinade 1 hour or up to 8 in the refrigerator. After it is done marinating grill it until internal temperature reaches 130-135 on a meat thermometer (ours was medium rare in the middle and a little more done towards the outsides). Remove from grill and let rest for 10 minutes before slicing in very thin slices. Alternatively, if you do not have a grill, preheat oven to 450, and cook in oven for about 20-45 minutes (depending on the size of your tenderloin and how well done you like it) remove and let rest to keep the juices in, and then slice very thin.

For the Guacamole: Mince and chop up all the vegetables, put everything in a bowl and mash everything together until it gets to the desired consistency.

For the Tacos/assembly: Preheat oven to 350 and warm the taco shells for 3-5 minutes to get them warm. For the assembly serve taco shell, 2-3 slices of the beef tenderloin, 2-3 tbs of guacamole, and a sprinkling of the cheese. Watch them disappear!