Preheat oven to 425°F (220°C). Line one or two large baking sheets with parchment paper.

In a small bowl, combine the cumin, coriander, sumac, salt, and cayenne pepper (if using).

In a large bowl, toss the cauliflower florets and chickpeas with the olive oil and spice mix until well coated. Spread them out in a single layer on the prepared baking sheets. Roast for 20 minutes, flip the cauliflower and shake the chickpeas, then roast for another 15 minutes, or until the cauliflower is fork-tender and the chickpeas are golden.

While the vegetables roast, soak the cashews in boiling water for 15 minutes, then drain. Add the cashews, avocado, lime juice, cilantro, jalapeño brine, garlic, salt, and 3 tablespoons of water to a high-speed blender. Blend until completely smooth, scraping down the sides as needed and adding more water, 1 tablespoon at a time, until the mixture is creamy and spreadable.

Heat the pitas in a dry skillet over medium heat or microwave for 10–20 seconds until warm and pliable.

Assemble and serve.

Spread a generous layer of avocado crema on each pita. Top with roasted cauliflower, chickpeas, and fresh cilantro. Serve immediately.