Preheat the oven to 425°F and set aside a sheet pan.
Add the cubed sweet potatoes, chickpeas, and chopped red onion to the sheet pan. Drizzle with olive oil and sprinkle with the garlic powder, dried thyme, smoked paprika, and cumin. Toss to coat and spread everything out in a single layer.
3 cups sweet potatoes, 1 can chickpeas, 1 medium red onion, 1 tablespoon olive oil, 1 teaspoon garlic powder, 1/2 teaspoon dried thyme, 1/2 teaspoon smoked paprika, 1/2 teaspoon cumin
Roast for 25 to 30 minutes, flipping halfway through, until the sweet potatoes are tender and lightly caramelized on the edges.
While the vegetables roast, add the apple cider vinegar, Dijon mustard, maple syrup, olive oil, and dried thyme to the bottom of a large bowl and whisk together.