Rinse the quinoa until the water runs clear. Cook with a two-to-one water-to-quinoa ratio. Bring to a simmer, cover, and cook on low heat until fluffy.
Peel and cube the sweet potatoes. Toss with a little oil and salt, then roast at 400°F (200°C) until edges caramelize and centers are tender.
Halve the cherry tomatoes and roast briefly, or leave raw for fresher flavor.
Season chicken breasts with salt, pepper, and optional spices. Bake or grill until fully cooked, then slice.
Prepare the tahini dressing by whisking tahini, water, lemon juice, olive oil, maple syrup, garlic, and salt until smooth. Adjust water to reach desired consistency.
Assemble the bowl by layering quinoa, roasted sweet potatoes, cherry tomatoes, corn, diced onions, roasted red peppers, and sliced chicken.
Top with torn cilantro and drizzle generously with lemon-tahini dressing.
Serve warm or at room temperature. Optionally, add a squeeze of fresh lemon over the top for extra brightness.