Preheat oven to 425°F (220°C).

On a large baking sheet, toss cauliflower florets with olive oil, paprika, cumin, cardamom, turmeric, cayenne pepper, lemon juice, chopped garlic, kosher salt, and black pepper. Ensure everything is well coated.

Bake for 15 minutes. Toss the cauliflower and bake for another 15 minutes, or until tender and lightly charred at the edges.

While cauliflower bakes, prepare the zhug: Combine all zhug ingredients (cilantro, parsley, jalapeños, garlic, cardamom, cumin, coriander, salt, pepper, olive oil, lemon juice) in a food processor or blender. Pulse until finely chopped.

If the zhug is too thick, add water, 1 tablespoon at a time, until desired consistency is reached. Taste and adjust salt if needed.

Assemble the pitas: Spread a generous layer of zhug onto each pita. Top with fresh lettuce, the roasted cauliflower, and thinly sliced red onion. Drizzle with more zhug. Add tahini and harissa if desired.