1. Preheat oven to 400°.
2. Combine first 3 ingredients on a jelly-roll pan. Drizzle with 1 tablespoon oil; toss to coat. Bake at 400° for 20 minutes or until cauliflower is tender, stirring once. Place remaining 1 tablespoon oil, cauliflower mixture, quinoa, and next 4 ingredients (through nuts) in a large bowl; toss.
3. Combine tahini and remaining ingredients in a small bowl, stirring with a whisk. Drizzle tahini mixture over cauliflower mixture.