One of the places I used to work was in a college town and one of our best sellers after the bars was simple. We took a garlic toasted hoagie roll, smeared BBQ sauce on one half, laid out a good amount of crumbled sausage, then topped with onion, green pepper if you liked it, and laid on some cheese. It was oven baked for a few minutes just to warm up the meat, melt off the cheese.
They were decent, but I have an idea it was more the bar than the hoagie that was selling them.