Preheat your oven to 400°F (200°C).
Wash and cube the sweet potatoes into bite-sized pieces.
Toss the cubed sweet potatoes with olive oil, smoked paprika, cumin, salt, and pepper.
Spread the seasoned sweet potatoes on a baking sheet and roast for 25-30 minutes, flipping halfway.
While the sweet potatoes roast, rinse and drain the black beans.
In a skillet over medium heat, warm the black beans and corn until heated through.
Prepare your toppings: chop the avocado, dice the red onion, and prepare cilantro if using.
Once the sweet potatoes are done, remove them from the oven and let cool for a few minutes.
Assemble the taco bowls by layering ingredients in bowls: start with sweet potatoes, followed by black beans, corn, onion, and avocado.
Drizzle lime juice over the assembled bowls and garnish with cilantro if desired.