Whisk together olive oil, garlic powder, paprika, salt, and pepper. Add chicken breasts, coat evenly, cover, and marinate in the refrigerator for at least 30 minutes.

Preheat oven to 425°F (220°C). Peel and cube sweet potatoes, toss with olive oil, cinnamon, and salt, spread on baking sheet, and roast for 25-30 minutes.

Preheat grill over medium-high heat. Remove chicken from marinade, grill for 6-8 minutes per side until internal temperature reaches 165°F (75°C). Let rest before slicing.

Whisk tahini, lemon juice, water, and salt and pepper until smooth. Adjust consistency with more water if necessary.

In a serving bowl, layer cooked greens, grains, sliced grilled chicken, and roasted sweet potatoes. Drizzle with tahini dressing and add toppings.