Put meat into bowl, rolling it in the Rub mixture until it is coated evenly.
Cover the meat with wax paper or plastic wrap and let sit at room temperature for 10 minutes, no longer
Place the meat in heavy duty aluminum foil and fold foil to make a sealed pouch.
Place tenderloin in baking dish or pan and put into oven.
Bake for 2 hours or until it shreds with a fork.
Transfer meat to a serving dish and let rest for 5 minutes.
Warm the tortillas by loosely wrapping them in a damp paper towel and microwave on high for 30 to 45 seconds.
Shred with fork or slice tenderloin into very thin pieces and serve hot with warm tortillas, avocados, salsa, and cilantro in separate bowls so all family members can make their own tacos