Preheat the oven to 400 degrees F. Line two sheet pans with parchment.
Drain and rinse the chickpeas. Pat them dry with paper towels and remove any loose outer skins. In a small bowl, whisk together the lemon juice, olive oil, cumin, salt and pepper. Stir in the chickpeas. Use a slotted spoon to transfer them to one of the prepared sheet pans.
Place the cauliflower in a single layer on the other prepared sheet pan. Toss with olive oil salt and pepper.
Bake the chickpeas and cauliflower for 25 – 30 minutes until the chickpeas are crisp and golden brown, and the cauliflower is starting to brown at the edges.
For the dressing, whisk together the tahini, lemon juice, water, garlic, salt and pepper in a small bowl.
In a large bowl, combine the chickpeas, cauliflower, scallions, chives, pomegranate seeds and pistachios. Drizzle with the tahini dressing before serving.