Step 1: Preheat and Prepare Vegetables

1. Preheat the oven to 400°F (200°C). Line a baking sheet with parchment paper or lightly grease it with oil.
2. In a large bowl, toss the sweet potatoes with 1 tablespoon of olive oil, cumin, smoked paprika, garlic powder, turmeric, salt, and pepper until well coated. Spread them evenly on half of the baking sheet.
3. In the same bowl, mix the chickpeas with 1 tablespoon of olive oil, salt, pepper, and cayenne pepper (if using). Spread the chickpeas evenly on the other half of the baking sheet.

Step 2: Roast the Sweet Potatoes and Chickpeas

1. Roast in the preheated oven for 25-30 minutes, tossing halfway through, until the sweet potatoes are tender and slightly caramelized, and the chickpeas are golden and crispy.
2. Remove from the oven and let them cool slightly while you prepare the other ingredients.

Step 3: Cook the Grain Base

1. While the vegetables are roasting, cook quinoa or brown rice according to package instructions. Use vegetable broth instead of water for added flavor. Once cooked, fluff with a fork and set aside.

Step 4: Make the Tahini Dressing

1. In a small mixing bowl, whisk together the tahini, lemon juice, minced garlic, maple syrup (or honey), salt, black pepper, and ground cumin. Gradually add warm water, 1 tablespoon at a time, until you reach a smooth and pourable consistency.

Step 5: Assemble the Bowl

1. In a serving bowl, layer the mixed greens, a portion of the cooked quinoa or brown rice, and a generous serving of roasted sweet potatoes and chickpeas.
2. Add a handful of thinly sliced red onion, a few slices of avocado, and a sprinkle of chopped cilantro or parsley.
3. Drizzle the tahini dressing generously over the top and serve immediately.