In a slow cooker add roast and make incisions in any fatty areas. Add water (enough to just cover roast) and set cooker to a high temperature. At around the two hour mark add the taco mix (add more water if mix is too thick) and continue cooking for another two hours or until beef can easily be pulled apart with a fork. Remove from slow cooker and drain if beef is too watery. Set to cool in a bowl. When cool enough to handle, form into patties (size will depend on the buns you are using).
*Optional: preheat over to 400 and place patties on a baking sheet. Bake until edges start to crisp. Place, still warm, patties on toasted buns. Top finished burgers with your choice of taco style fixings such as lettuce, salsa, cheese, jalapeno peppers, tomato, sour cream, onions, etc.