Begin by heating a large cast iron skillet to medium high heat. While you wait for the pan to heat up, season the shrimp. In a small bowl, mix together salt, pepper, and cumin. Pour evenly over the shrimp.
Once the pan is hot, add 1 tbsp oil, then the garlic. Cook for less than 1 minute, then toss in the shrimp. Cook the shrimp on one side for 2-3 minutes, then flip over.
After flipping over the shrimp, add 2 tbsp lime juice and tequila to the hot skillet. Mix around with a wooden spoon, deglazing the pan from the seaoninings and garlic. Cook for another 2 minutes, or until shrimp is opaque and cooked through. Remove from heat and top with 1/4 cup cilantro.
Meanwhile, make the slaw (if using). Toss together the cabbage, 1/4 cup cilantro, 1 tbsp oil, 3 tbsp lime juice, and the red onion. Sprinkle with some sea salt.
Toss shrimp and the tequlia lime juice on top of the slaw and serve.