Step 1: Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper.
Step 2: In a large bowl, toss the cauliflower florets with olive oil, cumin, chili powder, smoked paprika, garlic powder, and salt until evenly coated.
Step 3: Spread the cauliflower in a single layer on the prepared baking sheet and roast for 20-25 minutes, tossing halfway through, until the edges are charred and crispy.
Step 4: While the cauliflower roasts, whisk together the Greek yogurt, lime juice, and chopped cilantro in a small bowl to create the crema.
Step 5: Warm the tortillas in a dry skillet or over a gas flame until soft and slightly charred.
Step 6: Assemble the tacos by filling each tortilla with roasted cauliflower, a drizzle of cilantro lime crema, and a garnish of cabbage and pickled onions.