Mix together the beef, salt, pepper, garlic powder, worcestershire sauce and 1/2 chopped white onion in a bowl. Then, press the beef evenly into a 9×13 inch pan. It should be a flat layer. Bake for 25 minutes at 350.
While the beef is cooking, sauté the other 1/2 white onion in a little olive oil and add a pinch of salt and pepper. Cook until golden and delicious.
Now get the rolls ready. Cut them in half lengthwise. Drain the beef when it’s done and carefully set it aside on a cutting board.
Place the bottoms of the buns in the baking dish. Then place the beef on top. Layer on the cheddar slices or crumbled blue cheese. Finish with the remaining bun tops.
Brush the tops with melted butter, and then it’s back in the oven for 5 minutes.
The cheese should be melty and the tops golden brown. Cut into individual sliders and serve. Oh and don’t forget your sautéed onions and sliced pickles if you want to load them up.