01 - Preheat oven to 425°F (220°C). Line a baking sheet with parchment paper.
02 - Toss sweet potato cubes with a drizzle of olive oil, salt, and pepper. Arrange on the baking sheet in a single layer. Roast for 25 to 30 minutes, stirring halfway, until golden and tender.
03 - While sweet potatoes roast, combine quinoa, water, and 1/2 teaspoon salt in a saucepan. Bring to a boil, then reduce to a simmer, cover, and cook for 15 minutes. Remove from heat, let stand for 5 minutes, then fluff with a fork.
04 - In a small bowl, whisk together tahini, lemon juice, water, olive oil, maple syrup, garlic, salt, and pepper until smooth. Adjust water for desired consistency.
05 - Divide greens among four bowls. Add a scoop of quinoa, roasted sweet potato, cherry tomatoes, red onion, and avocado slices to each bowl.
06 - Drizzle each bowl with lemon-tahini dressing. Garnish with feta, seeds, and fresh herbs if desired. Serve immediately.