Preheat the oven to 400°F (200°C). Line two baking sheets with parchment paper.
Spread the sweet potatoes on one sheet and the chickpeas on the other. Drizzle both with olive oil, and season with salt and pepper. Sprinkle the chickpeas with garlic powder.
Bake the chickpeas for 15 minutes, tossing halfway through, until golden and slightly crisp. Bake the sweet potatoes for 20 minutes, or until lightly browned and tender.
Meanwhile, make the couscous. In a small pot, bring the vegetable broth to a boil. Stir in the couscous, cover the pot, and remove from heat. Let sit for 5 minutes, then uncover and fluff with a fork. Set aside.
Place shredded kale in a large bowl and squeeze over lemon juice. Use your hands to massage the leaves for 1-2 minutes, until tender and slightly softened.
Make the dressing by whisking together tahini, garlic paste, Dijon mustard, maple syrup, lemon juice, and water. Add extra water, a little at a time, until the dressing reaches your desired consistency.
Assemble the bowls by layering couscous, massaged kale, roasted sweet potatoes, roasted chickpeas, sliced apples, feta cheese, and chopped pecans. Drizzle generously with the tahini dressing and serve.