Finely chop the head of cauliflower (by hand or use a food processor)
Add coconut oil, onion, tomatoes, cauliflower and all the seasonings to a large saute pan over medium heat. Cook uncovered for 10 - 15 minutes, stirring occasionally.
While the cauliflower crumble cooks add the sauce ingredients into a high-speed blender and blend on high until smooth.
Warm the taco shells and top with cauliflower crumble, shredded cabbage, sunflower seeds, lime wedge, red pepper sauce and diced cilantro.