Preheat oven to 375 degrees or 350 convection roast.
Place cabbage and onion in a bowl and toss with olive oil and salt and pepper. Then place them on a cookie sheet lined with tinfoil.
Place broccoli and brussels sprouts in a bowl and toss with olive oil and salt and pepper. Then place them on a second cookie sheet lined with tinfoil.
Put the vegetables in the oven and roast for about 45 minutes until soft and slightly browned.
While the vegetables are cooking, slice raw chicken into little pieces. Place in a bowl and toss with olive oil, onion salt and garlic powder. Set aside.
Cook quinoa according to package directions. Set cooked quinoa aside.
Combine all Honey Mustard Sauce ingredients together in a small bowl. Whisk together until smooth. Set aside.
When vegetables are nearly done cooking, heat up a cast iron pan. Add grapeseed oil.
Cook chicken until nice and brown, about 15 minutes.
Remove vegetables from oven.
Assemble bowls with chicken, quinoa and vegetables. Top with a little swirl of barbecue sauce and honey mustard sauce.