Heat griddle until it reaches about 400-425 degrees F.
While griddle is heating up, add marinara sauce to a small saucepan and place it on the griddle surface to warm.
Add a small amount of oil or beef fat to the griddle and use a spatula to spread it around the surface. Then, add the diced onions and saute for about 1 minute. Move the onions to the side of the griddle to continue to cook.
Add the pepperoni and salami to the griddle. Then, add the ribeye to the griddle in a thin even layer, keeping the sliced Italian meats and ribeye steak separated. Use your bench scraper to "chop" the pepperoni and salami on the griddle until it is in bite-sized pieces (or you can chop the Italian meats before adding them to the griddle). Season the ribeye with an all-purpose seasoning or a mix of salt, pepper, and garlic powder.
While the meat and onions are cooking, prepare the hoagie rolls. Cut the rolls in half, but not all the way through. You want the two sides of the bread to be attached on one side, similar to a hot dog bun. Add a small dash of balsamic vinegar in to the cut side of the bread (optional). Set the bread to the side.
Combine the ribeye, pepperoni, salami, and diced onions on the griddle. Saute for about 2 minutes. Then, portion out the meat mixture into 4 long piles, about the same length as your bread rolls.
Add 1-2 tablespoons of marinara sauce to the top of each cheesesteak portion. Top each with 2-3 slices of provolone. Then place a prepared bread roll opened up, and cut side down on top of each portion of cheesesteak. Allow the bread to steam and help melt the cheese for about 1-2 minutes.
Using a griddle spatula, transfer the cheesesteak portions to the hoagie rolls. Add your sandwich toppings and serve warm.