Preheat the oven to Gas Mark 6.
Chop the cauliflower into small fine florets and place them on a large oven tray. Add the onions and chickpeas to the same tray.
Drizzle with olive oil and season with salt and pepper. Add the garlic, smoked paprika and cayenne and toss the cauliflower, onions and chickpeas until coated evenly.
Roast in the preheated oven for 20 minutes, then stir, return them to the oven, and roast for an additional 10-15 minutes.
Roughly chop the parsley and set aside.
Combine the ingredients for the dressing in a small bowl and whisk to combine.
Assemble the salad by combining the cauliflower, chickpeas and onion in a bowl. Drizzle with dressing and top with parsley.