Add the oil to a skillet and heat. Add the ground beef and cook until browned.
Add the onions and cook until translucent. Add the garlic and cook for a little. Add the salt and pepper along with the cumin, Chile powder and oregano. Combine and cook a few minutes.
Add the potatoes, tomatoes and beef stock. Bring to a boil, reduce the heat to a simmer, cover and cook until potatoes are soft and most of the liquid has absorbed. Check for seasoning and adjust.
Serve with rice and tortillas or use as a filling for tacos, burritos, etc.