Line a large baking sheet with parchment paper or aluminum foil.
Place sweet potato chunks, red pepper, and onions on the baking sheet, and toss with oil, spices, salt, and pepper, coating all the veggies well with the spices. Spread the veggies out on the tray in a single layer so they roast well. Bake in 375° oven for 30 minutes.
Carefully remove from oven, and stir in black beans and corn, spreading out to a single layer again. Return the baking sheet to the oven, and roast for 10 minutes.