Heat a large non-stick skillet over medium high heat. Add about a tablespoon of olive oil and the onions. Season with salt and cook until softened, about 5 minutes. Add black pepper and garlic powder and cook for a minute more. Add in the ground beef, breaking up with a spatula, and season with more salt. Cook the beef until browned and no pick remains, about 8 minutes total. Pour in the marinara.
On a griddle or grill, cook the hot dogs over high heat until crisped, about 3 minutes total. Build the dogs by adding a hot dog to each bun, topping with the beef mixture, garnishing with cheese and green onion before devouring.