When I was in high school, my best friend's mom used to make this all the time. The first time I had it, I thought I had died and gone to heaven. I immediately asked for the recipe and brought it to my mom. Now I often make it to bring to gatherings and it never fails to be a hit. You can easily double it for larger crowds if you have a big enough crock pot. I sometimes cheat and use my pressure cooker, but my husband insists the crock pot makes it better. This is served on hoagie rolls, and all you soft white bread fans need to listen to me when I say that this is one time when crustier is better. The juicy goodness will soak right through a soft roll in two seconds flat. We also like to make burritos with the leftovers, so I guess you could make it just for that purpose if you wanted.
Aprox 3-4 lbs beef roast (cheap cuts work fine), trimmed of excess fat
3-5 cloves garlic, peeled and lightly smashed
1 small white or yellow onion, thinly sliced and separated into rings
1 Tbsp salt
1 Tbsp black pepper
1 Tbsp crushed red pepper (half if you want less heat)
1 Tbsp Italian seasoning
1 jar pepperoncini peppers (be careful not to get the really salty, bitter ones. I often find the store brand ones to be the best. Kroger's store brand pepperoncinis are awesome.)
Place the roast in crock pot (no need to brown first). Add water to be even with the thickness of the roast, but not covering the top. Sprinkle all seasonings over roast. Lay onion rings and crushed garlic on top, along with 6-8 pepperoncinis. Cook in crock pot until completely tender and falling apart (time depends on how fast you need it--you can cook it all day on low or about 6 hours on high, usually).
Remove meat to a large platter or shallow bowl and let sit just until cool enough to handle. Meanwhile, strain broth into a large bowl, discard solids (you can keep the onion if you want but the peppers will be gross and you're going to put more in anyway). Return broth to crock pot, then shred the meat and add to the broth. Put in 1/2 cup of pepperoncini juice and simmer another half hour at least (or just let it sit if it's going to be awhile or you are taking it somewhere). At this step, I also add a few more coarsely chopped pepperoncinis (or the banana peppers that come sliced in rings), but you can opt to serve these as a garnish if you prefer. Serve with a large slotted spoon.