In a nonreactive bowl, combine 1/3 cup of the tequila, the soy sauce, the zest and juice of 1 lime, the cumin, and freshly cracked black pepper. Add the steak to the marinade and let it sit at room temperature for 30 minutes, or refrigerate it for no longer than 1 hour.
In a small bowl combine the remaining lime zest, lime juice and sour cream. Cover and refrigerate until ready to use.
Strain the steak from the marinade. Pour the marinade into small saucepan over medium-high heat and bring to a simmer. Let it simmer until it reduces by a third, about 10 to 15 minutes.
Heat a large skillet over high heat. Add the steak and cook until it barely starts to brown. Switch off the heat, then add the marinade reduction, the white vinegar, and the remaining tequila.
Prepare the taco shells, either by frying or heating in an oven.
For service, rub the shells with the reserved lime rinds. Add the some of the beef, taco slaw, sour cream and onions to each taco. Garnish with the cilantro and Cotija cheese. Serve and enjoy!
Prepare all the vegetables and add to a large bowl. Season them with the salt and pepper and add the vinegar. Toss to combine.