Place the steak in a baking dish and top with Old El Paso chopped green chiles, garlic, the zest of one lime, 1 teaspoon salt, and 1/2 teaspoon black pepper. Rub the mixture over the steak on all sides and set aside.
Preheat the grill to high. Allow the steak to marinate in the green chile relish, while you chop and prepare the remaining ingredients.
Lift the steak out of the green chile relish and place it on the hot grill. Sear for 3-4 minutes per side. Take the steak off the grill and tent it with foil to keep warm. Then sauté the remaining green chile relish in a small skillet until slightly charred, 5-8 minutes on medium-high. Scoop it out of the skillet and place the charred green chile relish on top of the steak.
Slice the limes into wedges. Then place the tortillas on a microwave-safe plate and cover them with a damp paper towel. Heat for 45-60 seconds to warm through. Slice the steak into thin strips, against the grain.
Place several slices of steak with relish on each warm tortilla, then top with chopped green onions, cilantro, sliced avocado, and crumbled queso fresco. Serve with lime wedges.