Begin by making the chimichurri sauce. Finely chop the parsley and add it to a mixing bowl. Add the dried oregano, chili flakes, minced garlic, diced shallot, red wine vinegar, and olive oil to the bowl. Stir until well combined. Season with salt and pepper to taste. Set the sauce aside.
Next, prepare the beef ribs. Preheat your smoker to 300 degrees. Season the beef ribs generously on all sides with salt, pepper, and garlic.
Once the smoker is ready, place the ribs inside and smoke them until they reach an internal temperature of 203 degrees. This can take anywhere from 4-6 hours depending on the size of your ribs.
Once the ribs are cooked through, remove them from the smoker and let them rest in foil for at least 30 minutes. This allows the meat to reabsorb its juices and makes it easier to slice.
While the ribs are resting, heat a large pan over medium heat. Add the tortillas to the pan and slather them with a bit of oil. Once the pan is heated, add shredded cheese to the tortillas and let it melt.
Once the cheese is melted, slice the beef ribs into bite-size pieces. Top the tortillas with the ribs and chimichurri sauce.
Remove the tacos from the pan once the cheese is fully melted. Serve immediately and enjoy! These tacos are best served warm and fresh, but they can also be reheated in the oven or microwave for later.