Mix together the olive oil, cumin, oregano, salt, lime juice and zest, cilantro, garlic, and jalapeno pepper (if using) and whisk well.
Pour half of the marinade over the steak and stir to coat well. Cover and let marinate while you prepare the vegetables.
Remove the stems and cut the red, yellow, and orange peppers in half. Remove the seeds then slice into thin strips.
Cut the onion into thin strips as well.
Set a large skillet over medium-high heat and add about a teaspoon of olive oil to coat the bottom with. Dump in the peppers and onions and cook until soft, about 5 minutes.
Remove the vegetables to a plate and cover with aluminum foil to keep warm.
Next, add the steak strips to the same pan that was used to cook the peppers. Cook until just done, about 5-7 minutes.
Stir the peppers and reserved marinade back into the pan and heat to warm through.
Warm your Mission tortillas in a dry skillet, or microwave oven according to the directions on the back of the package.
Divide the steak fajita mixture between the tortillas, fold in the sides, then roll towards you to close.
Tips and Techniques
For best results use skirt or flank steak. If you can't find either of those cuts, you can substitute other thinly slices cuts of steak but it may not be as tender.
Marinating the steak longer (1-4 hours) will result in more flavor, however, because we save half the marinade to use at the end, there is still plenty of flavor in this recipe.
Remove the seeds and membrane from the jalapeno if you prefer your fajitas to be milder.
Please note that the nutritional information label at the bottom of this recipe does NOT include the tortillas as the information is not in the program that I use to calculate nutritional estimates. Each tortilla contains 5 grams of net carbs. See the back of the package for the remaining nutritional facts. Thank you for your understanding!