Preheat the oven to 400ºF.
Place the cauliflower, red pepper slices, red onion slices, and chickpeas in a large bowl.
In a small bowl, whisk together the oil, lemon juice, garlic, cumin, paprika, coriander, salt, turmeric, and black pepper.
Pour the spice mixture over the vegetables and beans; toss with a spoon or your hands until all pieces are well coated.
Spread out the vegetables and beans in an even layer on one very large baking sheet or two medium-size baking sheets. Roast in the oven for 30 to 35 minutes or until cauliflower pieces are tender.
Meanwhile, in a small bowl, whisk together the tahini, lemon juice, and maple syrup. (Just before serving, whisk 2-3 tablespoons of warm water into the tahini mixture until you’ve reached your desired dressing drizzling consistency).
Build bowls with lettuce, cucumber, and tomatoes. Top with the roasted vegetables and beans. Drizzle the tahini sauce over top and garnish with lemon wedges, fresh herbs, cashews, and/or toasted sesame seeds, as desired.