Preheat the oven to 425°F. Line a baking sheet with parchment paper.
In a large bowl, toss the diced potatoes with olive oil, chili powder, cumin, garlic powder, onion powder, salt, and pepper until evenly coated.
Spread the seasoned potatoes in a single layer on the prepared baking sheet. Roast in the oven for 25-30 minutes, or until golden brown and crispy, stirring halfway through.
While the potatoes are roasting, prepare the toppings. In a medium bowl, combine black beans, corn, cherry tomatoes, avocado, cilantro, and lime juice. Mix gently to combine.
Once the potatoes are done, remove them from the oven and let them cool slightly.
To assemble the taco bowls, divide the roasted potatoes among serving bowls. Top with the bean and corn mixture, shredded cheddar cheese, and a dollop of sour cream or Greek yogurt if desired.
Serve immediately and enjoy your delicious potato taco bowls!