Rinse the quinoa under cold water to remove bitterness. In a pot, combine the quinoa with a 2:1 water-to-quinoa ratio. Bring to a boil, then reduce to simmer, cover, and cook for about 15 minutes until tender. Let sit covered for an additional 5 minutes.

Preheat your oven to 400°F (200°C). Spread the diced sweet potatoes and beets on a baking sheet. Drizzle with 1 tablespoon of olive oil, season with salt and pepper, then roast for 25-30 minutes until tender and caramelized.

In a small bowl, whisk together tahini and lemon juice. Gradually add water while whisking until desired consistency is reached. Adjust seasoning with salt.

In a large mixing bowl, combine the cooked quinoa, roasted sweet potatoes, and beets. Drizzle with tahini dressing and gently toss to combine. Garnish with fresh parsley and optional ingredients (feta, walnuts, arugula, cranberries) before serving.