Preheat your oven to 400 F and line a 13x18-inch sheet pan with parchment paper.
Place the onion, cabbage, potatoes, squash and Brussels sprouts on your prepared pan. Drizzle with olive oil and season with salt and pepper. Toss to evenly coat the vegetables and spread them out into a single layer.
Roast for 40 minutes, or until the vegetables are tender and lightly browned. Season to taste with more salt and pepper, if needed.
Tahini Sauce
Put the tahini, lemon juice, mustard, and maple syrup in a small bowl and whisk until smooth.
To assemble the Buddha bowls, spoon the cooked quinoa into bowls. Top with the roasted vegetables and garnish with avocado slices and parsley. Drizzle the tahini sauce over each bowl to serve.
Recipe by Go Dairy Free at https://www.godairyfree.org/recipes/buddha-bowls