1) Set the slow cooker to high and add the oil. Dice the onions and the tomatoes and sautéthem for two or three minutes.
2) Stir in one of the taco seasoning packets and the broth. Add roast to the slow cooker, set it to low and cook for 6-8 hours.
3) After the cooking time remove the roast and shred it. Add the beef back in to the slow cooker and mix well also add the second Taco seasoning package.
4) Add to taco shells and top with favorite toppings.
