Preheat oven to 425°F. In a large bowl, toss diced potatoes with olive oil, chili powder, smoked paprika, garlic powder, cumin, salt, and pepper until evenly coated.

Spread seasoned potatoes in a single layer on a metal baking sheet without overcrowding. Roast for 25-30 minutes, flipping halfway through with a spatula, until edges are golden brown and crispy.

While potatoes roast, heat a large skillet over medium-high heat. Add ground beef and cook, breaking up with a wooden spoon, until browned with no pink remaining (6-8 minutes). Drain excess fat, then add taco seasoning and 1/4 cup water. Simmer for 3-4 minutes until thickened.

Remove potatoes from oven and immediately transfer to serving bowls while still hot. Quickly sprinkle shredded cheese over hot potatoes so it melts.

Spoon seasoned beef or beans over cheesy potatoes. Add toppings: sour cream, salsa, green onions, cilantro, and any optional toppings like tomatoes, corn, jalapeños, or avocado.

Serve immediately while warm and cheese is gooey. Let everyone add extra toppings or hot sauce to taste.