i have a pretty good recipe.....
This recipe is my own. I pretty much came up with it. My ex live in chicago all her life and she loves mine chicago style beef sandwiches. We had resteruants that opened around my area called "Chicago style" and mine kill it. It is pretty simple too. One thing i would never use is a crock pot. I Just don't think it taste good.
OK this is what i do. I get a relatively lean beef roast 4-6 pounds. I puncture the meat all over and insert garlic cloves in it. I sear it on all sides in a skillet with oil and season with salt and pepper.
I then take a flat dish and pur about 2-3 cans of beef broth/stock in it. You can either add a dark beer or not. Sometimes i do sometimes i don't. I then add oregeno, salt, pepper, and italian seasonings. Cook this in the oven uncovered at a relatively low temperature (250). Cook the meat till it has an internal temperature of 135-140. I don't know exactly how long this takes because i just use a electic meat thermometer that is in the meat the entire cooking time. You want the meat to be medium rare. Do not go over this temperature or your meat will dry out. Now time to cool. Put the meat into the refrigerator after it cool with the juices. The next day heat the beef broth to where its just slightly warm (do not boil this will overcook the meat). Slice the meat very thin with a meat slicer and throw it in the warm beef broth and let it warm threw (5) minutes. Serve on crusty rolls with either Gardeniera or sliced cherry peppers. My ex used to dip her sandwich in the broth. I like mine dry because i think it makes if fall apart. But i think you will agree this is one of the best italian subs you can get anywhere.
Trying to slice the meat before its cooled. If you do this the meat will fall apart. I like my sliced thin like authentic sandwiches. If you like it shredded then go ahead.
Overcooking the meat - it will curl especially if you overcook it in the beef broth and it will be rubbery.