Preheat your oven to 400°F (200°C) and lightly grease a large baking dish.
In a large bowl, toss the peeled and diced potatoes with olive oil, garlic powder, onion powder, salt, and pepper. Spread the potatoes evenly on a baking sheet and roast for 20-25 minutes, until golden and fork-tender.
While the potatoes are baking, heat a skillet over medium-high heat. Add the ground beef and cook, breaking it up, until no longer pink—about 5-7 minutes. Drain excess fat.
Sprinkle the taco seasoning over the cooked beef, pour in the water, and stir well. Allow the mixture to simmer for 2-3 minutes until thickened.
Remove the potatoes from the oven and transfer to your greased baking dish. Spoon the seasoned taco beef evenly over the potatoes.
Sprinkle the shredded cheddar cheese on top of the beef and potatoes.
Return the dish to the oven and bake for 8-10 minutes, or until the cheese is completely melted and bubbling.
Remove from the oven and let cool for a few minutes. Add your favorite toppings before serving—sour cream, diced tomatoes, green onions, cilantro, or jalapeños.
