Heat the oven to 220°C/425°F. Spread the chickpeas, cauliflower and aubergine on a baking sheet in a single layer (use two if you need to). Drizzle over the olive oil and spices and toss together. Roast for 30-40 minutes.
Place all of the sauce ingredients in a food processor and blend until smooth. Add salt and pepper as needed.
Fill each pitta with the roasted vegetables and chickpeas and top with the avocado sauce.
Nutrition information is an estimate and will vary depending on the exact ingredients used.