Preheat the oven to 350 degrees.
In a large bowl, combine the ground beef, egg, garlic salt, pepper, parmesan, and Italian seasoning until thoroughly mixed. Take a golf ball-sized amount of the beef mixture and roll it into a ball. Repeat with the rest of the beef mixture, setting the meatballs aside on a plate.
Heat oil in a pan over high heat. Sear meatballs on one side for about one to two minutes, then flip. Cook for another one to two minutes, then remove the meatballs from the pan and drain any excess fat. Pour the marinara sauce into the pan and place the meatballs in the sauce. Cook for about eight to 10 minutes, flipping the meatballs in the sauce, until the sauce has reduced to a thick consistency. Remove from heat.
Cut the 4x3 sheet of dinner rolls in half lengthwise. Arrange the bottom half into a 9x13 baking pan. Place the meatballs on each roll. Put cheese on top.. Cover with the top half of the dinner rolls.
In a small bowl, combine the melted butter, garlic, oregano and parmesan, stirring until evenly mixed. Pour the garlic butter mixture over the top of the sliders. Bake for 20 minutes until the rolls are golden brown and cheese is melted. Cut into individual sandwiches, and serve!