Heat oil in a large skillet over medium-high heat. Rub beef roast with salt and pepper, and sear on all sides. You're not cooking it here; just get it a nice brown color to seal in all those yummy juices.
Place the roast in the crock pot, and cover it with water, beef broth, onion soup packets, and a bay leaf.
Cook 8 to 10 hours on low; or 4 to 6 hours on high. It's done when the meat falls apart when shredded with a fork--the longer you cook it, the more tender it will be.
Pile the hoagie buns with the shredded meat, and top with cheese. Broil the sandwiches open-faced for a few minutes--keep a close eye on 'em, or the bread will get too toasty! You just want your cheese to get nice and melty.
Serve sandwiches with cups of the juices for dipping.