Preheat oven to 325
In an oven safe pot heat oil over medium heat
Add onion and cook for 5 minutes until soft, remove from the pot
Add another splash of oil
Pat dry steak & rub all sides with taco seasoning
Sear the steak on both sides for about 3 minutes until a golden crust forms
Turn off the heat, remove steak and add the broth
Using a rubber or wooden spatula scrape the bottom to ensure nothing is sticking
Return the steak and the onions
Cover with lid and place into the oven for 3 hours
Remove from pot & shred, if it doesn't easily shred, bake for another 30 minutes, return beef back into the sauce and mix well
Assemble bowls with all the toppings
Store beef in the fridge for up to 4 days