Cook the rice of your choice according to package directions.
In a large skillet, saute the onion and the sweet potatoes in the olive oil over medium heat. Cook until tender, about 25 minutes. Add the spices and stir.
Add the black beans and corn, and cook for about 5 minutes, until the corn is done and everything is heated through.
Put a scoop of rice in each bowl and top with the vegetables. Garnish with fresh cilantro.
Notes
Store leftovers in the refrigerator. They should stay fresh for about 3 days.You can also use this veggie filling for tacos or burritos.