Throw the steak and all the ingredients for the marinade into a large plastic food bag. Once all in, toss the bag to coat the meat.
Place in refrigerator to marinate for at least one hour, or overnight
Remove meat from marinade, discarding leftover juice
Heat up your grill or grill pan to a very high heat. Cook the steak as you desire (personally, I love it a bit rare...).
Allow the meat to cool for at least ten minutes before slicing it into thin strips.
Let's get going on the sauce! To do this, combine the chipotles, mayonnaise, lime juice and salt. Stir well.
Heat up a sauté pan to a medium heat
Put one tortilla in the pan and sprinkle about a quarter cup of cheddar cheese on top. Place another tortilla on top, and cook until the cheese starts to melt, then flip over once. Make sure you only cook until the tortilla turns soft - not until crispy!
Time to assemble your taco! Apply as much guacamole as your heart desires to your tortilla.
Add a few slices of steak, then add pico de gallo, cotija cheese and some of the sauce. Garnish with cilantro.