1. Prep the Oven and Vegetables: Preheat your oven to 400°F (200°C). On a large rimmed baking sheet, toss your sweet potatoes, broccoli, bell pepper, and red onion with the olive oil, salt, and pepper. Use your hands to ensure every piece is evenly coated.
2. The Roast: Spread the vegetables out in a single layer. Don’t overcrowd them. If they are touching, they will steam instead of caramelizing. Roast for 25–30 minutes, tossing halfway through, until the edges of the potatoes are golden and the broccoli is crisp-tender.
3. Cook the Grain: While the oven does the work, rinse your quinoa thoroughly under cold water to remove any lingering bitterness. Combine with 2 cups of water in a small pot. Bring to a boil, then reduce heat to low, cover, and simmer for 15 minutes. Once the water is absorbed, remove from heat and let it sit, covered, for 5 minutes before fluffing with a fork.
4. Whip the Dressing: In a small bowl, whisk the tahini, lemon juice, and maple syrup together. It will seize up at first—don't worry! Gradually add the warm water, one tablespoon at a time, whisking continuously until the mixture turns smooth, pale, and pourable.
5. Assemble: Scoop a generous bed of quinoa into your favorite bowl. Arrange the roasted vegetables on top and finish with a heavy drizzle of the lemon-tahini sauce.

This bowl is a dream for meal preppers. If you want to save time during the week, roast a double batch of vegetables on Sunday. They keep beautifully in the refrigerator for up to 4 days.

I recommend storing the components in separate containers if possible. The quinoa will stay fluffy, and the vegetables will maintain their texture better than if they were tossed in dressing beforehand. When you are ready to eat, reheat the grains and veggies in a pan over medium heat with a tiny splash of water—this "steams" them back to life. Whisk a fresh batch of dressing or add a little extra water to your pre-made dressing to reach that silky consistency again.