To make your marinade, zest the lime using the small holes of a box grater or micro plane. Add the zest to a large non-reactive bowl. Juice the lime and add the juice to the bowl along with 2 tablespoons of extra-virgin olive oil, taco seasoning, and salt. Add the beef and mix well to coat. Cover and refrigerate for at least 1 hour or over night.
When you are ready to cook, preheat a skillet over medium heat. Add 2 tablespoons of extra-virgin olive oil and sauté the peppers and onions until tender, but still firm, about 5-7 minutes. Remove the onions and peppers to a plate and set aside.
In the same skillet, add the beef and marinade and cook over medium heat until your desired doneness, about 1-2 minutes for rare and 4-5 minutes for well done. Return the peppers and onions to the skillet, combine and heat through. Cover and keep warm until you are ready to serve.
Spoon the filling down the center of a warm tortilla, add your desired toppings, roll or fold, and enjoy. Makes 8 tortillas.