First start but heating your cast iron skillet or sauté pan with some olive oil over medium heat. Then add in the onion and potatoes.
Sauté for a few minutes until the onions are soft and fragrant.
Then add in the ground beef and cook until browned. Drain any grease if necessary.
Next add in the packet of taco seasoning and the can of diced tomatoes (plus the liquids).
Give everything a stir and cover and cook about 10 minutes until the potatoes are fork tender.
Top with shredded cheese, let melt a bit, then serve hot.
