Preheat the oven to 400 degrees.
Rub the potatoes all over with the olive oil and place them directly on a center oven rack. Bake for 50 to 60 minutes, until the potatoes are tender when you squeeze them gently. Remove the potatoes from the oven and set aside. Reduce the oven temperature to 350 degrees.
Meanwhile, to prepare the steak, in a large shallow dish, combine the soy sauce, Worcestershire sauce, liquid smoke, garlic powder, and onion powder and mix well. Season the steak with salt and pepper. Add the steak to the marinade and turn to coat. Marinate for 20 minutes (and up to 24 hours; when marinating longer than 1 hour, refrigerate the steak, then pull it from the fridge 30 minutes before cooking).
To prepare the onions, heat 1 tablespoon of the oil in a large skillet over medium heat. Add the onions and cook until golden brown and tender, about 6 to 8 minutes, stirring frequently (if they are getting browned too quickly, reduce the temperature to medium-low).
Season the onions with salt and pepper and set aside.
To cook the steak, brush a stovetop grill pan or griddle with olive oil and preheat to medium-high. Add the steak to the hot pan and cook for 3 to 4 minutes per side for medium-rare, or slightly longer for more fully cooked meat.
Remove the steak from the pan and let rest for 5 minutes before slicing. Slice the steak, across the grain, into very thin strips.
Using a sharp knife, halve each potato lengthwise and transfer the potatoes to a shallow baking dish. Stuff the potatoes with the steak and onions, and then top them with the two cheeses.
Transfer the potatoes to the oven and bake for 5 minutes, until the cheese melts.
Serve with hot peppers and ketchup.