Preheat your oven to 425°F (220°C). Wash and peel the potatoes, then cut them into roughly 1-inch chunks.
For extra crispy potatoes (optional), place the cut potatoes in a large bowl of cold water and let them soak for 20-30 minutes. Drain them well and pat completely dry with paper towels.
In a bowl, toss the dried potato chunks with 1 tablespoon of oil, about half the chili powder, and a pinch of salt until evenly coated.
Spread the potatoes in a single, even layer on a baking sheet. Roast for 20-25 minutes, turning halfway through, until the edges are golden brown and the centers are tender.
While the potatoes are roasting, heat a large skillet over medium-high heat. Add the remaining chili powder, salt, garlic, and pepper, and toast for 30 seconds until fragrant.
Add the ground beef to the skillet. Cook, breaking it up with a spoon, until it is browned and cooked through.
Stir in the frozen corn and water. Bring to a simmer, then cover the skillet and let it cook for 5 minutes until the corn is heated through and the liquid has slightly reduced.
To build the bowls, start with a layer of hot roasted potatoes. Spoon the seasoned beef and corn mixture over the top.
Finish with your desired toppings, such as shredded cheddar cheese, guacamole, pico de gallo, and a dollop of sour cream. Serve immediately.
