To make the marinade, blend all the ingredients, except the steak of course, with a blender on high power for 2 minutes. Place the steak in a large ziplock bag and pour in the marinade. Marinade for 1 to 2 hours.
Grill or broil the steak for 6-8 minutes on each side over medium-high heat (don't move the steak around once you have placed it on the hot surface, and only flip once).
Remove from the heat, allow it to cool, then slice into small bite-size pieces.
For the guacamole:
In a medium size bowl, mash the avocados with lime juice, salt, cumin, and cayenne. Stir in the jalapeno, tomatoes, cilantro, and garlic. Cover and set aside.
To assemble:
Preheat the oven to 350 degrees F.
Scoop the refried beans into a microwave safe bowl, and microwave on high for 2-3 minutes, or until warmed through.
Line a large baking sheet with foil. Spread the tortilla chips on the sheet. Sprinkle the cheese over the chips, then add the garlic and jalapeno. Scoop little mounds of refried beans over the cheese, then top with diced steak. Bake in the oven for 10 minutes, or until all the cheese is melted.
Top the nachos with little mounds of guacamole and pico de gallo. Scoop ⅓ cup sour cream into a medium ziplock bag, the snip off one corner. Pipe the sour cream over the nachos. Sprinkle cilantro over the top and serve immediately with the extra guacamole on the side.
Recipe by Sprig and Flours at http://www.sprigandflours.com/carne-asada-nachos/