Step 1

Add flank steak to a large plastic ziplock bag. Add lime juice, 1/4 cup olive oil, chili powder, cumin, garlic powder, and cayenne to the bag as well. Zip up. Massage marinade into meat. Refrigerate for at least 2 hours and up to 8.

Step 2

Preheat the grill to a high heat - about 450 degrees. Place a grill pan or sheet on one side of the grill. Once the steak has marinated, remove and sprinkle with 1 1/2 teaspoons of salt on both sides. Add the peppers and onions to a medium bowl. Toss with remaining 2 tablespoons olive oil. Season with remaining 1/2 teaspoon salt and a little bit of pepper.

Step 3

Add the pepper to the grill. Cook for 3-4 minutes and then add steak on the uncovered side of the grill. Use tongs to toss the peppers. Close the grill. Let the steak cook for about 4 minutes. Use tongs to flip the steak over. Toss the peppers again. If they are charred enough, remove from the grill.

Step 4

Cook the steak another 3-4 minutes or until it reaches your desired doneness. (For skirt steak you really want medium-rare to medium which is an internal temperature of 140-145 degrees. It will increase 5 degrees as it rests. Remove the steak and peppers from the grill. Let the steak rest for 10 minutes.

Step 5

Use a sharp knife to cut the steak against the grain into thin slices. Serve in warm tortillas with your favorite toppings.