Preheat oven to 400°F
Remove the base of the cauliflower. Compost/discard the base. Chop the remaining cauliflower bits into bite sized pieces and place the pieces into the large mixing bowl.
Open the two cans of chickpeas, pour into colander, and rinse the chickpeas until the water leaving the colander runs clear. Pour the rinsed chickpeas into the large bowl with the cauliflower.
Peel remove the ends of the red onion. Compost/discard the peel and ends. Chop the red onion into pieces (i like them a bit larger) and add the chopped red onion to the large bowl with the chickpeas and cauliflower.
Pour the 1 tablespoon of olive oil over the large bowl of chickpeas, cauliflower, and onion. Mix together to coat the vegetables in the olive oil.
In the small bowl, add the above mentioned measurements of the chili powder, garlic powder, cumin, and salt. Mix the spices together. Pour the small bowl of spices over the large bowl of the chickpeas, cauliflower, and onion. Mix the items in the large bowl until the chickpeas, cauliflower, and onion all are semi-evenly coated with the spice mixture.
Pour the large bowl mixture onto the baking sheet. Try to make sure the mixture is spread out evenly onto the baking sheet. Once the oven is preheated, place the mixture and baking sheet into the oven. While these are baking is a great time to prep your toppings.
After 10 minutes, stir the filling around on the tray to prevent sticking and allow for an even back. Cook in total for 20-30 minutes. The filling is ready when the cauliflower is tender.
Assemble your taco! Squeeze some fresh lime juice over the filling and top as desired. Enjoy!