Preheat the oven to 400 degrees. Line a large baking sheet with foil.
Prick the potatoes with a fork. Toss in a large bowl with olive oil, salt and pepper.
Place the potatoes on the baking sheet and bake for 15 minutes. Flip potatoes over and bake for another 15-20 minutes or until cooked through.
Remove potatoes from the oven and set aside to cool.
In a medium skillet, cook the beef until fully browned over medium high heat. Then transfer to a cutting board and dice into small pieces.
Add olive oil to the skillet over medium heat along with the onions and bell pepper. Cook for 5-7 minutes, stirring occasionally until softened. Remove from the heat and set aside.
Slice the cooled potatoes in half and use a spoon to carefully scoop out the inside, leaving a thin layer around the edges of the skin to make them sturdy enough to hold the filling.
In a large bowl, stir together the potato filling, steak, onions and bell pepper. Season to taste with salt and pepper. Scoop the filling back into each of the potato halves. Top with shredded cheese.
Return to the oven and bake for 5-7 minutes or until the cheese is melted.