Preheat the oven to 425°F (220°C).
Start with the quick-pickled onions. Place the sliced red onion in a bowl with the grated garlic, lime zest, lime juice, red wine vinegar, maple syrup, cilantro, and a pinch of kosher salt.
Toss thoroughly to coat the onions. Cover and refrigerate while preparing the remaining ingredients.
Drain and rinse the chickpeas. Place them on a clean kitchen towel and gently pat them as dry as possible. Removing excess moisture helps them become crisp in the oven.
Transfer the chickpeas to a baking tray. Add approximately 1 tablespoon avocado oil and a pinch of salt, then toss to coat.
Spread the chickpeas into a single layer and roast on the upper oven rack for 20 minutes.
Remove the tray and allow the chickpeas to cool for 5–10 minutes. Sprinkle with 1 teaspoon garlic powder and ½ teaspoon ground coriander.
Toss the chickpeas with the spices, then return them to the oven for approximately 10 minutes, or until mostly crisp and golden.
Meanwhile, arrange the cauliflower on a separate baking tray.
Add the remaining garlic powder, coriander, onion powder, dried thyme, salt, and 1–2 tablespoons avocado oil. Toss thoroughly.
Arrange the cauliflower with the cut sides facing down against the baking sheet. Roast for 20 minutes.
Toss the cauliflower, then return it to the oven for another 10–15 minutes, until browned around the edges and tender inside.
While the vegetables roast, prepare the chipotle yogurt sauce. Add the chipotle peppers, plant-based yogurt, vegan mayonnaise, lime juice and zest, maple syrup, garlic, cilantro, and a generous pinch of salt to a small blender.
Blend until smooth. If you don't have a blender, finely mince the chipotle peppers and whisk everything together in a bowl.
Add 1–2 tablespoons water if necessary to create a smooth, drizzleable consistency.
Once the cauliflower and chickpeas are roasted, transfer the chickpeas to the cauliflower tray.
Drizzle several spoonfuls of chipotle sauce over the roasted mixture and toss gently with tongs.
Warm the pita breads according to their package instructions.
Spread 1–2 spoonfuls of chipotle sauce over each warm pita.
Add lettuce, a generous portion of the roasted chickpea and cauliflower mixture, and some of the quick-pickled onions.
Fold or roll the pita securely around the filling and serve immediately.