Preheat oven to 450F. Chop cauliflower into florets. Line a baking sheet with aluminum foil or other non-stick lining.* Toss florets with cumin, sumac, chili powder, garlic powder, salt, and olive oil, and place on the baking sheet. Bake for about 22-25 minutes, until they begin to crisp and brown.

Meanwhile, prepare the lentil filling. Sauté the chopped onion and garlic in a medium saucepan over medium-high heat in the olive oil.** Once fragrant and the onion begins to brown, after about 5 minutes, add the cooked lentils. Add the cumin, chili powder, and salt. Cook until lentils absorb the flavors, about 8-10 minutes.

Prepare the lime tahini. Whisk tahini and lime juice in a small bowl. Add water and salt and whisk. If you would like a thinner sauce, whisk in more water ½ tablespoon at a time until desired consistency is reached.
Chop the cilantro and slice the avocado, in preparation for assembly. Warm the corn tortillas in the microwave for 30 seconds in between paper towels to make assembly easier.

Assemble the tacos. Put a scoop of the lentil filling in the bottom of each taco, followed by a few cauliflower florets. Place some avocado slices into each taco. Drizzle each taco generously with lime tahini, and then garnish with chopped cilantro and pomegranate seeds. Serve immediately.