Slice and then chop the onions into quarter slices
Heat a pan on medium low heat and add 1 tbsp butter and 1 tbsp olive oil. Cook onions on low heat, stirring frequently until onions are golden in color. I like my onions well cooked for cheesesteaks, so this takes at least 20 minutes.
Put onions in a bowl and set aside.
Cook your beef with a little salt, black pepper, and garlic powder.
When beef is only a little bit pink, add the onions to the pan with the steak and finish cooking until steak is fully cooked.
Preheat oven to 350F
Slice the slider bread in half, so that you can seperate the tops from the bottoms
Place the bottoms in a Baking Dish. I like to seperate each bottom piece, but I still keep the sliders in the original shape of 3 sliders wide, 4 sliders long. Then I cut each slice of cheese into 4s and place 2 pieces on each piece of bread(half will be used on top). Then I top the cheese with the meat and onion mixture. Then I add two squares of cheese to each slider, and finally, I top it with the tops of the bread.
Tightly wrap with aluminum foil and bake for about 15 minutes.
After 15 minutes, take off the aluminum foil and bake until cheese is very melty and the tops of the buns are lightly golden.