Preheat your oven to 425°F. Line a large baking sheet with parchment paper. Add the cauliflower, sweet potato to the sheet in the center. Drizzle with the 2 tbs olive oil and all the spices listed in the Tacos section. Mix to coat all with your hands. Spread out evenly and roast for 30 minutes, quickly tossing/flipping half way through (they should be fork tender). Evenly sprinkle the black beans and add back into the oven for 5 minutes.
Assembly:
Char your tortillas on your gas grill or in a pan to warm through and make them pliable.
In a medium bowl, roughly mash your avocado with some Sriracha.
Chipotle Crema:
Combine your crema ingredients in a small blender or food processor - pulse until smooth. Taste and adjust anything if needed.