Preheat the oven to 425°F. Line 1 large baking-sheet with parchment-paper or aluminum-foil for easy clean-up and then put aside.
Prep the veggies: put the cauliflower-florets and diced sweet-potato in a large-bowl. Then drizzle the olive-oil on top, season with the garlic powder, paprika, chili powder, cumin, salt and oregano.
Squeeze the lime-juice on top, toss to blend. Then transfer the veggies into the prepared baking-dish, arranging everything in a uniform coating, with a great deal of breathing space.
Roast the veggies for 25minutes, then providing the baking-sheets a shake shake around halfway through. Add the black-beans into the sheet-pan, then seasoning with another pinch of salt, then put the pan in the oven for 5minutes to warm the black-beans through. Remove from the oven and put aside.
Prep taco assembly: Meanwhile as the veggies roast, prep the rest of taco fixins:
Prep the chipotle lime cashew crema: Add all listed ingredients at a high-speed-blender, blend to combine. Then transfer into a bowl and put aside or store in an airtight container in the fridge up to 1-week.
Mash the avocado: add all listed ingredients in a bowl. Use a fork to mash to a preferred consistency. Put aside.
Char a few tortillas: I enjoy tortillas with a tiny bit of char.
Assemble the roasted veggie tacos: smear some mashed avocado on each tortilla. Top with a generous spoonful of roasted veggies. Drizzle some chipotle lime cashew crema along the top. Finish with a few freshly chopped cilantro.