Pat the skirt steak dry with paper towels and season generously on both sides with salt and pepper.
Place a cast iron skillet over high heat until it begins to smoke lightly.
Add the olive oil, then carefully lay the steak in the hot skillet.
Cook the steak for 3-4 minutes per side for a perfect medium-rare.
Transfer the steak to a cutting board and let it rest for at least 5 minutes.
While the steak rests, prepare the guacamole. Halve the avocados, remove the pits, and scoop the flesh into a bowl.
Add the fresh lime juice, chopped cilantro, salt, and pepper. Mash with a fork until you reach your desired consistency.
Thinly slice the rested steak against the grain into bite-sized strips.
Divide the steak among four plates.
Top each portion with shredded pepper jack cheese, a dollop of guacamole, and a spoonful of sour cream.
Finish with a splash of chipotle tabasco and a sprinkle of fresh cilantro.
Serve immediately with low-carb tortillas.