Trim all excess fat off of roast (I use the cheapest cut the store has or on sale). Place in the bottom of crockpot.
Put in diced onions and pepper. Sprinkle dry italian dressing over the top. Pour the whole bottle of dressing on. Then the broth. The broth is just to keep the meat from drying out you might need more.
Cook on High for 4-6 hours till tender. Shred with 2 forks. mix well. You can leave it on high or turn it down on low if its gonna be several hours before you eat.
split a hoagie place 2 slices of cheese on bottom (I use provolone but you could use any cheese that melts good). Add beef. Top with your choice of sauteed onions, peppers, mushrooms anything you like. Bake sandwich for about 5-10 mins at 350 just long enough to melt the cheese, you could also just microwave it for about 30-45 seconds.