Preheat oven to 400°F. Line a baking tray with aluminum foil or spray with oil.
Add quinoa, water, and a pinch of salt into a medium pot. Bring to a boil. Reduce heat and cook for 16 minutes, covered.
Remove from heat and fluff with a fork. Set aside on a warmer.
Add brussel sprouts and onion slices to your baking sheet.
Drizzle with olive oil and add salt.
Toss the vegetable mixture to coat evenly.
Place in the oven and cook for 20-30 minutes, removing to toss every 15 minutes.
Add the pecans to the baking sheet in the last 2 minutes of cooking time to toast (optional).
In a large bowl, toss together the cooked quinoa, roasted vegetables, pecans, and cranberries. Season to taste with salt and pepper.
Before serving, garnish with additional pecans and parsley.