Heat ⅛ to ¼ cup olive oil in a nonstick skillet over medium heat. Add the diced potatoes, cover, and cook until golden brown and crispy on most sides—about 10 minutes. Covering helps steam them inside. Transfer potatoes to a paper towel-lined plate and set aside.

In the same skillet, add the ground beef. Sprinkle with 1 tsp salt, garlic powder, cumin, and pepper. Cook over medium-high heat, breaking up the meat, for 8–10 minutes—until beautifully browned.

Add minced garlic and diced onion. Cook another 2–3 minutes until onions are translucent and garlic is aromatic.

In a blender, combine tomatoes, serrano chiles, water, a pinch of salt, and Mexican oregano. Blend until smooth.

Pour the tomato-chile sauce into the beef mixture. Bring to a gentle boil, taste, and adjust salt as needed. Add the potatoes, stirring to coat in sauce. Lower heat and simmer for 7–10 minutes, allowing the sauce to thicken and the flavors to meld.

Remove from heat, taste, and season one last time. Serve hot with rice, warm tortillas, or simply on its own—just like mom used to make.