Preheat the oven to 400°F (200°C). On a large baking sheet, toss the cubed sweet potato, broccoli, and chickpeas with olive oil, paprika, garlic powder, salt, and pepper. Spread in a single layer and roast for 20-25 minutes, tossing halfway through, until potatoes are fork-tender and chickpeas are slightly crisp.

Combine the rinsed quinoa and vegetable broth in a saucepan. Bring to a boil, then reduce heat to low, cover, and simmer for 15 minutes. Remove from heat and let sit, covered, for 5 minutes. Fluff with a fork and stir in 1 tablespoon of lemon juice.

In a small bowl, whisk together the tahini, 2 tablespoons of lemon juice, maple syrup, and minced garlic. Gradually whisk in warm water one tablespoon at a time until the dressing reaches a smooth, pourable consistency.

Divide the fluffy quinoa into four bowls. Top each with a portion of the roasted veggie mix and drizzle with the lemon-tahini dressing.