Prepare the Vegetables: In a large mixing bowl, combine shredded green cabbage, red cabbage, carrots, red onion, and chopped cilantro. Toss to mix evenly.
Make the Dressing: In a small bowl, whisk together lime juice, tequila, olive oil, honey, cumin, chili powder (if using), and a pinch of salt and pepper. Taste and adjust seasoning.
Combine: Pour the dressing over the vegetable mixture. Toss thoroughly to coat. If using Greek yogurt or mayonnaise, add it to the dressing before tossing for creaminess.
Chill and Serve: Cover and refrigerate for at least 10 minutes to let flavors meld. Serve chilled as a side or taco topping.