2½ pounds flank steak
4 cloves garlic, minced
¼ cup plus 2 tablespoons extra virgin olive oil
3 tablespoons Worcestershire sauce
¼ cup freshly squeezed lime juice (from 2 to 4 limes)
1 tablespoon ground cumin
1 tablespoon chili powder
1 tablespoon sugar
¼ teaspoon crushed red pepper flakes
1 teaspoon kosher salt
Olive oil cooking spray
4 bell peppers (any color), stemmed, seeded, and thinly sliced
1 yellow onion, thinly sliced
8 to 12 small (6-inch) flour or corn tortillas, for serving
¼ cup chopped fresh cilantro leaves
Salsa, sour cream, sliced avocado, and Cotija cheese, for serving

Place the flank steak in a large zip-top bag or a shallow glass baking dish. Whisk together the garlic, olive oil, Worcestershire sauce, lime juice, cumin, chili powder, sugar, red pepper flakes, and salt in a small bowl. Reserve ¼ cup of the marinade for the vegetables and pour the rest over the flank steak, turning it to coat. Close up the bag or cover the baking dish and marinate the steak in the refrigerator for at least 2 hours, and up to 12. When you’re ready to cook, preheat the oven to 450°F with one rack about 4 inches from the broiler, another rack in the center position, and another in the bottom position. Line a sheet pan with aluminum foil, and mist it with the cooking spray. Toss the peppers and onion with the reserved ¼ cup marinade in a large bowl and spread them evenly on the prepared pan. Roast on the center rack until softened and starting to brown, 10 to 15 minutes. Remove the pan from the oven and turn the oven to broil. Wrap a stack of tortillas in aluminum foil and set it aside.
Push the peppers and onion to the perimeter of the pan. Remove the flank steak from the marinade, allowing any excess liquid to drip off the meat, and place it in the center of the pan, surrounded by the vegetables. Place the pan on the top rack and broil the steak, flipping it once, until it begins to char on the outside and an instant-read thermometer inserted into the thickest part of the meat registers 125°F for rare or 135°F for medium-rare, 3 to 5 minutes per side. While the steak cooks, place the foil-wrapped tortillas on the bottom rack to warm through. Once the steak is finished cooking, remove the pan from the oven and turn the oven off. Leave the tortillas in the oven to continue warming while the steak rests. Allow the steak to rest, loosely covered with foil, for 10 minutes before slicing it thinly against the grain. Sprinkle with the cilantro. Serve the steak warm with the peppers and onion and tortillas. Pass the salsa, sour cream, avocado, and cheese at the table.