Toss the sweet potato and broccoli in a large bowl with 1 tablespoon olive oil, the remaining 1/4 teaspoon cumin, 1/2 teaspoon salt and a few grinds of pepper. Spread in a single layer on a baking sheet and roast on the upper oven rack, stirring once, until lightly browned and tender, about 25 minutes. Meanwhile, cook the quinoa as the label directs.