1. Preheat oven to 425° (220°C). Combine cauliflower and 4 tsp (20 mL) margarine and arrange on two-thirds of a rimmed baking sheet. Combine red onion and 2 tsp (10 mL) margarine and arrange on remaining third of baking sheet. Roast until cauliflower is browned and slightly crispy and onion is tender; about 25 minutes.
2. Meanwhile, cook quinoa according to package directions. Fluff with a fork and stir in mint. Combine remaining margarine, turmeric, cumin and red pepper flakes and stir into quinoa. Divide quinoa between 4 bowls. Top each evenly with cauliflower, red onion and avocado.