Start by preheating your oven to 425 degrees and either line two cookie sheets with a Silpat or spray with oil and set aside. Make sure your rice is cooking or already cooked.
Take your peeled and chopped sweet potato and place it in a single layer on one of the cookie sheets. Take the other cookie sheet and place the chopped cauliflower; you can take a teaspoon of oil and move it around on the cauliflower; if you are oil-free, leave it off. Sprinkle with salt. Bake this for 25 minutes.
At the 25 minute mark, pull the sweet potatoes out and add the chickpeas; if you are using oil, you can add some here; if not, that's totally fine. Then add 2-3 TB of taco seasoning. I usually use 2 ½ tbs. Take a spoon and mix around the seasoning and oil; if using, try to spread it as evenly as you can, and place it back in the oven.
Bake for another 20 minutes or until they are cooked to your desired crispiness.
Now build your bowl. Place rice on the bottom, layer with sweet potatoes/ chickpea and roasted cauliflower, then drizzle with your desired amount of tahini. You can add additional toppings like avocado, salsa, or whatever sounds good.