Chicken and Sweet Potato Bowls with Tahini Sauce

• 2 pounds sweet potatoes, cut into 1- to 2-inch cubes
• 15 ounces (1 can) chickpeas, drained and patted dry
• 2 tablespoons olive oil
• 1 teaspoon garlic powder
• 1 teaspoon ground cumin
• 1 teaspoon salt

Tahini Sauce:

• ¼ cup tahini
• 3 tablespoons lemon juice
• 2 tablespoons warm water
• 2 tablespoons olive oil
• 2 teaspoons honey
• 1 clove garlic, minced
• 1 teaspoon salt

Chicken Bowl:

• 4 cups arugula
• 2 cups cooked chicken, shredded
• 2 cups cooked quinoa
• 1 red bell pepper, chopped
• 1 avocado, diced