Preheat oven to 400°F (200°C). Toss potatoes with olive oil, salt, and pepper in an oven-safe skillet.

Roast potatoes for 20–25 minutes, flipping halfway, until golden and tender.

While potatoes roast, brown ground beef in a skillet over medium heat. Drain excess fat.

Add taco seasoning and water to beef. Simmer until thickened.

Combine cooked beef with roasted potatoes and mix gently.

Sprinkle cheese evenly over the top and return skillet to oven for 5–10 minutes until melted.