Preheat the oven to 350 degrees
First prepare the spice mix. Measure the cumin, garlic, coriander, chili powder, oregano and salt - combine and mix together well, set aside.
Next prepare the roast - Using a paper towel, blot the meat to remove the moisture. Then coat lightly with 1 tbsp olive oil, season generously with salt and pepper. Sear it well on ALL sides - about five minutes pre side.
Remove the roast from the pan and add onions and sauté for five minutes, then add a can of fire roasted tomatoes and sprinkle with half the spice mix. Stir well to combine.
Then nestle the roast into the sautéed onions and tomatoes. Sprinkle with the remaining spice mix. Cover tightly and insert into a 350 degree oven for three hours. When complete shred with two forks.
Slice and dice your favorite toppings, toast the tortillas and prepare yourself for an amazing meal!