01 - Preheat oven to 425°F (220°C). Line a baking sheet with parchment paper.
02 - Toss sweet potato cubes with olive oil, salt, and pepper. Arrange in a single layer on the baking sheet and roast for 25 to 30 minutes, stirring halfway through, until tender and caramelized.
03 - Combine quinoa, water, and salt in a medium saucepan. Bring to a boil over medium-high heat, then reduce heat to low, cover, and simmer for 15 minutes. Remove from heat and let rest for 5 minutes. Fluff with a fork.
04 - In a small mixing bowl, whisk together tahini, lemon juice, water, olive oil, maple syrup or honey, minced garlic, salt, and pepper until smooth. Adjust water for a pourable consistency if needed.
05 - Divide greens evenly among four serving bowls. Top each with a scoop of cooked quinoa, roasted sweet potato cubes, cherry tomatoes, red onion, and avocado slices.
06 - Drizzle each bowl with lemon-tahini dressing. Garnish with feta, pumpkin or sunflower seeds, and fresh chopped herbs if desired. Serve immediately.