Pulse the garlic, cilantro, lime zest, cumin, salt, and pepper in a small food processor for 20 seconds. With the processor running, add the tequila.
Place the tilapia fillets into a 1-gallon zip-top bag, add the paste, and move around the coat each fillet. Work as much air out of the bag as possible, seal, and set aside at room temperature for 20 minutes.
Heat an nonstick electric griddle to 375ºF. I really like a griddle for this, but in a pinch, you can do this in a cast-iron pan parked over medium heat for 10 minutes.
Brush the griddle with the olive oil and cook the fillets until just cooked through and opaque, about 3 minutes per side. Cut into strips and serve in warm tortillas with crema, shredded red cabbage, and lime juice.