Preheat your oven to 325°F (163°C). Generously season your chuck roast on all sides with salt, pepper, and taco seasoning.

Place the roast in a Dutch oven or baking dish. Cover tightly with a lid or foil and bake for 3 hours (or about 1 hour per pound).

Remove from the oven and check tenderness. If it doesn’t shred easily, return it to the oven for another 30 minutes. Once tender, shred with two forks.

Mix the shredded beef into the rendered fat. Turn the oven up to 425°F and roast uncovered for 10–15 minutes until the edges turn crispy and golden brown.

Warm your tortillas, then fill with crispy shredded beef, a scoop of guacamole, and a few pickled red onions. Garnish with fresh cilantro and enjoy!