Preheat the oven to 400°F (200°C). Line two baking sheets with parchment paper.
Add the cubed sweet potatoes to one baking sheet and the chickpeas to the other. Drizzle each with 1 tablespoon of olive oil. Season the sweet potatoes with ½ teaspoon salt, ¼ teaspoon black pepper, and cumin. Season the chickpeas with the remaining ½ teaspoon salt, ¼ teaspoon black pepper, and garlic powder. Toss each until evenly coated.
Roast the chickpeas for 15 minutes, tossing halfway through, until golden and slightly crisp. Roast the sweet potatoes for 20 minutes, or until lightly browned and tender.
Meanwhile, make the couscous. Bring the vegetable broth to a boil in a small pot. Stir in the pearl couscous, reduce the heat to low, and cover. Simmer for 10-12 minutes, or until the liquid is absorbed and the couscous is tender. Remove from heat, let sit covered for 2-3 minutes, then fluff with a fork.
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, Dijon mustard, maple syrup, lemon juice, salt, and water. Add extra water, a little at a time, until the dressing reaches your desired consistency.
Assemble the bowls by layering kale, couscous, roasted sweet potatoes, roasted chickpeas, diced apples, vegan feta, and chopped pecans. Drizzle generously with the tahini dressing and serve.