Prepare the flank steak by placing the steak on a cutting board and cover it with plastic wrap or wax paper. 

Use a meat tenderizer to tenderize the meat and pound it to a 1-inch thickness. 

Next, add the garlic powder, chili powder, cumin, paprika, kosher salt, pepper, and brown sugar to a bowl and mix until combined. 

Pour the spice mix over the flank steak and massage the spices into the meat. Be sure the spices cover the steak completely. 

Let the flank steak rest in the spices for 20 minutes or longer for tender and flavorful meat. 

While the meat is sitting in the dry rub, add the cherry tomatoes, red onion, and cilantro to a medium-sized salad bowl and toss ingredients together. 

Drizzle the apple cider, lime juice, and salt over the vegetables and toss again. Place the tomato pico in the fridge.

Heat a large skillet or cast-iron skillet over medium/high heat. Add olive oil to the pan. 

When the olive oil is hot and fragrant, add the flank steak to the skillet. Be sure the flank steak is at room temperature and not cold. If the steak is cold and the skillet is hot, the spices will stick to the skillet.

Cook the flank steak for 4½ minutes on each side or until the internal temperature reaches 130-135ºF. 

Remove the steak from the skillet and let it sit for 10 minutes. 

Slice the steak into thin strips. 

Assemble the tacos by placing the tortillas flat. Start with ½ tablespoon of Greek yogurt slathered on the tortilla. Place a piece or two of steak over the Greek yogurt, a spoon full or the tomato pico, a sprinkle of cotija cheese, avocado and a squeeze of lime to the taco. Repeat until all tacos are assembled. 

Serve, and enjoy.