Lay out sliced steak on a lined baking tray and cook for 15-20 minutes at 375. When cool enough to handle, slice into ½ inch strips.
Place butter, ½ teaspoon of sea salt, and sliced onion in a large skillet over medium heat. Cook until the onion is soft and caramelized. About 20 minutes.
When onions are done, place sliced steak and queso into the same large skillet with the onions. Cook until the dish is heated through stirring occasionally.
If you feel you are running short or need an inexpensive way to stretch the dish, just add the optional browned ground beef.
Serve with slider buns or with regular buns, hoagies, etc.
Video
Notes
The ground beef will stretch out the dish without taking away from the flavor. You could also add ground turkey.