Mix avocado oil, lime juice, cilantro, garlic, fajita seasoning, salt and pepper in a small bowl, then pour it over the steak in a large bowl and toss to combine.

Cover with plastic wrap and let marinate at least 30 minutes, up to overnight.

Heat two tablespoons of the oil in a large skillet then add the red and yellow peppers and cook for 5-6 minutes or until they become tender and turn a light brown color.

Remove peppers from the pan and set aside for later.

Remove the steak from the sauce and cook it in the same pan as the peppers over medium heat on each side for about 6 minutes or until it reaches your preferred doneness.

Let it rest for 10 minutes then slice into long strips.

Add the lettuce to a large bowl then add the cherry tomatoes, cheese, some guacamole then the sliced steak.

Serve with freshly chopped cilantro and lime wedges if desired.