Directions

1. Combine the marinade ingredients in a measuring cup.
2. Place the steak in a shallow refrigerator container. Pour the marinade over the meat, allowing it also to flow beneath. Cover and refrigerate for 2 to 3 hours.
   
3. Before cooking, prep the vegetables as described. This also can be done in advance. Put in a zip-top plastic bag and refrigerate.
   
4. To cook the steak, heat a grill pan or cast iron pan for 2 minutes over high heat. Use a paper towel to wipe the marinade from the steak. Sprinkle with salt and pepper. Discard the marinade.
5. Sear the steak on the hot pan for about 3 minutes per side for rare, about 4 minutes per side for medium-rare, or until desired doneness. If you prefer, the steak can be cooked over a hot fire in a charcoal or gas grill. Be sure to quickly sear the surface, not allowing the meat to cook all the way through.
   
6. Use tongs to transfer the steak to a plate. Cover with tented foil to keep warm, allowing the meat to rest for 5 to 10 minutes.
7. Meanwhile, heat the olive oil in a large skillet over medium-high heat. Add the bell peppers and onion. Cook for 5 minutes, stirring occasionally, until crisp-tender.
   
8. While the vegetables are cooking, stack the tortillas between two damp paper towels. Microwave on HIGH for about 30 seconds, or until moist and warm.
9. Use a sharp knife to slice the steak across the grain into 1/4-inch strips. (It’s best to slice the meat at an angle, which makes it easier to get the slices thin).
   
10. Transfer the beef and vegetables to a bowl or serving plate. Place the warm tortillas in a covered basket. Accompany the presentation with bowls of lime wedges, salsa, and guacamole.
11. To make each fajitas, spoon some of the vegetables and beef mixture into a tortilla. Add a squeeze of lime if desired. Fold the tortilla over the filling.