The marinade. Combine the juice of one orange and lime, cumin, dried oregano, chili flakes, 4 cloves of chopped garlic, ¼ cup of olive oil and the cubed steak pieces into a large bowl. Give it all a toss, cover up the bowl and let it marinate in the fridge for three hours.
The pico de gallo. Combine the diced tomatoes and onion with some chopped parsley and the juice of one lime. Season with salt and set aside.
The chimichurri sauce. Combine the chopped cilantro, parsley, fresh oregano, shallot and Fresno chilies in a medium bowl with red wine vinegar, 4 cloves of chopped garlic and ¾ cup olive oil. Season with salt and pepper and set aside. Spoon over the steak when serving.
Step 1. Once the steak has been marinated, let it come to room temperature before searing it in a large skillet until medium-rare (about 5 minutes).
Step 2. Toast the flour tortillas on both sides in a small skillet until golden brown.
Step 3. Assemble the tacos by scooping some of the steak onto a tortilla, spoon over the chimichurri, add the pico de gallo and sliced avocado, and sprinkle on some shredded Parmesan. Enjoy!