Start by preheating your oven to 400°F (200°C). Wash the cauliflower and cut it into small florets so they roast evenly. Smaller pieces also become slightly crispy during baking.
Place the florets in a large bowl and drizzle with olive oil. Sprinkle chili powder, cumin, paprika, garlic powder, onion powder, salt, and black pepper over the cauliflower. Toss everything together until each piece is coated with the seasoning.
Roast the Cauliflower
Spread the seasoned cauliflower evenly on a baking sheet. Make sure the pieces are in a single layer so they roast properly instead of steaming.
Roast the cauliflower for about 25–30 minutes. Halfway through the cooking time, stir or flip the florets so all sides cook evenly. When done, the cauliflower should be tender inside and slightly crispy on the outside.
While the cauliflower is roasting, prepare the creamy sauce. In a small bowl, combine sour cream or Greek yogurt with chopped cilantro and fresh lime juice.
Add minced garlic, a pinch of salt, and a little black pepper. Stir everything together until the sauce becomes smooth and creamy. Taste and adjust lime or salt if needed.
Before assembling the tacos, warm the tortillas so they become soft and flexible. You can heat them in a dry skillet for a few seconds on each side.
Another option is warming them directly over a gas flame for a slightly charred flavor. Keep them wrapped in a clean towel to stay warm until serving.
Place a spoonful of roasted cauliflower in the center of each tortilla. Add sliced avocado, diced red onion, and shredded cabbage if using.
Drizzle the cilantro lime crema generously over the top. Finish with fresh chopped cilantro and serve immediately while everything is warm and flavorful.