Preheat the oven to 400F/ 204C.
In a small bowl, combine the chili powder, cumin, salt, onion powder, garlic, lime juice, olive oil and water. Stir to combine the marinade.
Add the cauliflower florets to a large bowl and the chickpeas to a medium bowl. Reserving about 2 tablespoons of the marinade and set aside for later, pour about three quarters of the rest on the cauliflower and a small amount over the chickpeas. Toss each the cauliflower and the chickpeas to coat completely. (The reserved liquid will be used after roasting.)
Lightly oil a sheet pan or a foil-lined sheet pan (for easer clean-up) and spread the cauliflower florets on the pan. Bake for 20 minutes.
While the cauliflower is roasting, make the Cilantro Lime Crema by adding all the ingredients to a small bowl, combining well and seasoning with salt and pepper. Set in the fridge until everything is ready.
After 20 minutes, toss the cauliflower a little and add the marinaded chickpeas, giving the pan a shake to make sure everything is spread out. Bake for another 10-15 minutes until the cauliflower is tender and the chickpeas are just starting to crisp up a bit. Remove from the oven, add the remaining 2 tbsps of the marinade, give a toss & set aside.
To assemble the tacos, heat a corn tortilla, then add a little of the cauliflower mixture, some cabbage, cilantro, avocado, jalapenos if using and top with the crema. If desired give another squeeze of fresh lime juice and a dash of your favorite hot sauce. Enjoy.
*swap the Greek yogurt for a non-dairy yogurt to make these completely vegan.