Preheat the oven to 425ºF (220ºC) and line a baking sheet(s) with parchment paper.
In a large bowl combine the cauliflower, onion, half of the olive oil, half of the spice blend, salt, and pepper. Mix well and transfer to the prepared baking sheet.
Add the chicken to the same bowl and toss with the remaining oil and spice blend. Season with salt and pepper and transfer to the sheet pan.
Place the baking sheet in the oven and bake for 30 minutes, flipping halfway, until everything is cooked through.
Meanwhile, whisk together the tahini, lemon juice, and water in a small bowl.
Divide the chicken and vegetables between plates and garnish with parsley. Serve with the tahini sauce on the side. Enjoy!
