Rinse quinoa under water for a couple of minutes. Bring water to a boil in medium pot, add quinoa, and cover. Cook for 15-20 minutes, until fully cooked through.
Meanwhile, heat olive oil in a large pan or dutch oven. Add onion and cook until translucent. Add cauliflower and curry powder. Mix well, then stir in broth and coconut milk. Cook for 15-20 minutes, until cauliflower is soft and sauce has thickened. Let cool for 10-15 minutes.
Place arugula leaves on large platter. Top with quinoa and then with cauliflower with sauce.
Recipe by Things I Made Today at https://www.thingsimadetoday.com/2013/05/23/curried-cauliflower-quinoa-and-arugula-salad/