01 - Set oven to 425°F (220°C) and line a baking sheet with parchment paper.
02 - Toss sweet potato cubes with a drizzle of olive oil, salt, and pepper. Arrange in a single layer on the sheet and roast for 25 to 30 minutes, stirring halfway, until caramelized and tender.
03 - In a saucepan, combine rinsed quinoa, 2 cups water, and 1/2 teaspoon salt. Bring to a boil, cover, reduce to a simmer, and cook for 15 minutes. Remove from heat and let stand covered for 5 minutes; fluff grains with a fork.
04 - In a small bowl, mix tahini, lemon juice, water, olive oil, maple syrup or honey, minced garlic, plus salt and pepper. Whisk until smooth, adjusting water for desired consistency.
05 - Divide greens among four bowls. Add portions of cooked quinoa, roasted sweet potatoes, cherry tomatoes, sliced red onion, and avocado to each bowl.
06 - Drizzle bowls with lemon-tahini dressing. Garnish with feta, roasted seeds, and fresh herbs as desired. Serve immediately.